---
title: "Index"
id: bookindex
pg_version: "20devel"
---

<a id="bookindex"></a>

# Index

## Symbols

- **$** — [Positional Parameters](sql-expressions.md#sql-expressions-parameters-positional)
- **$libdir** — [Dynamic Loading](xfunc-c.md#xfunc-c-dynload)
- **$libdir/plugins** — [Shared Library Preloading](runtime-config-client.md#runtime-config-client-preload), [Description](sql-load.md#sql-load-description)

## A

- **abbrev** — [Network Address Functions and Operators](functions-net.md)
- **ABORT** — [ABORT](sql-abort.md)
- **abs** — [Mathematical Functions and Operators](functions-math.md)
- **ACL** — [Privileges](ddl-priv.md)
- **aclcontains** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **acldefault** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **aclexplode** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **aclitem** — [Privileges](ddl-priv.md)
- **aclitemeq** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **acos** — [Mathematical Functions and Operators](functions-math.md)
- **acosd** — [Mathematical Functions and Operators](functions-math.md)
- **acosh** — [Mathematical Functions and Operators](functions-math.md)
- **administration tools**
  - externally maintained — [Administration Tools](external-admin-tools.md)
- **advisory lock** — [Advisory Locks](explicit-locking.md#advisory-locks)
- **age** — [Date/Time Functions and Operators](functions-datetime.md), [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **aggregate function** — [Aggregate Functions](tutorial-agg.md)
  - built-in — [Aggregate Functions](functions-aggregate.md)
  - invocation — [Aggregate Expressions](sql-expressions.md#syntax-aggregates)
  - moving aggregate — [Moving-Aggregate Mode](xaggr.md#xaggr-moving-aggregates)
  - ordered set — [Ordered-Set Aggregates](xaggr.md#xaggr-ordered-set-aggregates)
  - partial aggregation — [Partial Aggregation](xaggr.md#xaggr-partial-aggregates)
  - polymorphic — [Polymorphic and Variadic Aggregates](xaggr.md#xaggr-polymorphic-aggregates)
  - support functions for — [Support Functions for Aggregates](xaggr.md#xaggr-support-functions)
  - user-defined — [User-Defined Aggregates](xaggr.md)
  - variadic — [Polymorphic and Variadic Aggregates](xaggr.md#xaggr-polymorphic-aggregates)
- **AIX**
  - installation on — [AIX](installation-platform-notes.md#installation-notes-aix)
  - IPC configuration — [Shared Memory and Semaphores](kernel-resources.md#sysvipc)
- **akeys** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **alias**
  - for table name in query — [Joins Between Tables](tutorial-join.md)
  - in the FROM clause — [Table and Column Aliases](queries-table-expressions.md#queries-table-aliases)
  - in the select list — [Column Labels](queries-select-lists.md#queries-column-labels)
- **ALL** — [Subquery Expressions](functions-subquery.md), [Row and Array Comparisons](functions-comparisons.md)
  - GROUP BY ALL — [`GROUPING SETS`, `CUBE`, and `ROLLUP`](queries-table-expressions.md#queries-grouping-sets)
  - SELECT ALL — [`DISTINCT`](queries-select-lists.md#queries-distinct)
- **allow_alter_system configuration parameter** — [Platform and Client Compatibility](runtime-config-compatible.md#runtime-config-compatible-clients)
- **allow_in_place_tablespaces configuration parameter** — [Developer Options](runtime-config-developer.md)
- **allow_system_table_mods configuration parameter** — [Developer Options](runtime-config-developer.md)
- **ALTER AGGREGATE** — [ALTER AGGREGATE](sql-alteraggregate.md)
- **ALTER COLLATION** — [ALTER COLLATION](sql-altercollation.md)
- **ALTER CONVERSION** — [ALTER CONVERSION](sql-alterconversion.md)
- **ALTER DATABASE** — [ALTER DATABASE](sql-alterdatabase.md)
- **ALTER DEFAULT PRIVILEGES** — [ALTER DEFAULT PRIVILEGES](sql-alterdefaultprivileges.md)
- **ALTER DOMAIN** — [ALTER DOMAIN](sql-alterdomain.md)
- **ALTER EVENT TRIGGER** — [ALTER EVENT TRIGGER](sql-altereventtrigger.md)
- **ALTER EXTENSION** — [ALTER EXTENSION](sql-alterextension.md)
- **ALTER FOREIGN DATA WRAPPER** — [ALTER FOREIGN DATA WRAPPER](sql-alterforeigndatawrapper.md)
- **ALTER FOREIGN TABLE** — [ALTER FOREIGN TABLE](sql-alterforeigntable.md)
- **ALTER FUNCTION** — [ALTER FUNCTION](sql-alterfunction.md)
- **ALTER GROUP** — [ALTER GROUP](sql-altergroup.md)
- **ALTER INDEX** — [ALTER INDEX](sql-alterindex.md)
- **ALTER LANGUAGE** — [ALTER LANGUAGE](sql-alterlanguage.md)
- **ALTER LARGE OBJECT** — [ALTER LARGE OBJECT](sql-alterlargeobject.md)
- **ALTER MATERIALIZED VIEW** — [ALTER MATERIALIZED VIEW](sql-altermaterializedview.md)
- **ALTER OPERATOR** — [ALTER OPERATOR](sql-alteroperator.md)
- **ALTER OPERATOR CLASS** — [ALTER OPERATOR CLASS](sql-alteropclass.md)
- **ALTER OPERATOR FAMILY** — [ALTER OPERATOR FAMILY](sql-alteropfamily.md)
- **ALTER POLICY** — [ALTER POLICY](sql-alterpolicy.md)
- **ALTER PROCEDURE** — [ALTER PROCEDURE](sql-alterprocedure.md)
- **ALTER PROPERTY GRAPH** — [ALTER PROPERTY GRAPH](sql-alter-property-graph.md)
- **ALTER PUBLICATION** — [ALTER PUBLICATION](sql-alterpublication.md)
- **ALTER ROLE** — [Role Attributes](role-attributes.md), [ALTER ROLE](sql-alterrole.md)
- **ALTER ROUTINE** — [ALTER ROUTINE](sql-alterroutine.md)
- **ALTER RULE** — [ALTER RULE](sql-alterrule.md)
- **ALTER SCHEMA** — [ALTER SCHEMA](sql-alterschema.md)
- **ALTER SEQUENCE** — [ALTER SEQUENCE](sql-altersequence.md)
- **ALTER SERVER** — [ALTER SERVER](sql-alterserver.md)
- **ALTER STATISTICS** — [ALTER STATISTICS](sql-alterstatistics.md)
- **ALTER SUBSCRIPTION** — [ALTER SUBSCRIPTION](sql-altersubscription.md)
- **ALTER SYSTEM** — [ALTER SYSTEM](sql-altersystem.md)
- **ALTER TABLE** — [ALTER TABLE](sql-altertable.md)
- **ALTER TABLESPACE** — [ALTER TABLESPACE](sql-altertablespace.md)
- **ALTER TEXT SEARCH CONFIGURATION** — [ALTER TEXT SEARCH CONFIGURATION](sql-altertsconfig.md)
- **ALTER TEXT SEARCH DICTIONARY** — [ALTER TEXT SEARCH DICTIONARY](sql-altertsdictionary.md)
- **ALTER TEXT SEARCH PARSER** — [ALTER TEXT SEARCH PARSER](sql-altertsparser.md)
- **ALTER TEXT SEARCH TEMPLATE** — [ALTER TEXT SEARCH TEMPLATE](sql-altertstemplate.md)
- **ALTER TRIGGER** — [ALTER TRIGGER](sql-altertrigger.md)
- **ALTER TYPE** — [ALTER TYPE](sql-altertype.md)
- **ALTER USER** — [ALTER USER](sql-alteruser.md)
- **ALTER USER MAPPING** — [ALTER USER MAPPING](sql-alterusermapping.md)
- **ALTER VIEW** — [ALTER VIEW](sql-alterview.md)
- **ALTER_REPLICATION_SLOT** — [Streaming Replication Protocol](protocol-replication.md)
- **amcheck** — [amcheck — tools to verify table and index consistency](amcheck.md)
- **ANALYZE** — [Updating Planner Statistics](routine-vacuuming.md#vacuum-for-statistics), [ANALYZE](sql-analyze.md)
- **AND (operator)** — [Logical Operators](functions-logical.md)
- **anonymous code blocks** — [DO](sql-do.md)
- **any** — [Pseudo-Types](datatype-pseudo.md)
- **ANY** — [Aggregate Functions](functions-aggregate.md), [Subquery Expressions](functions-subquery.md), [Row and Array Comparisons](functions-comparisons.md)
- **anyarray** — [Pseudo-Types](datatype-pseudo.md)
- **anycompatible** — [Pseudo-Types](datatype-pseudo.md)
- **anycompatiblearray** — [Pseudo-Types](datatype-pseudo.md)
- **anycompatiblemultirange** — [Pseudo-Types](datatype-pseudo.md)
- **anycompatiblenonarray** — [Pseudo-Types](datatype-pseudo.md)
- **anycompatiblerange** — [Pseudo-Types](datatype-pseudo.md)
- **anyelement** — [Pseudo-Types](datatype-pseudo.md)
- **anyenum** — [Pseudo-Types](datatype-pseudo.md)
- **anymultirange** — [Pseudo-Types](datatype-pseudo.md)
- **anynonarray** — [Pseudo-Types](datatype-pseudo.md)
- **anyrange** — [Pseudo-Types](datatype-pseudo.md)
- **any_value** — [Aggregate Functions](functions-aggregate.md)
- **applicable role** — [`applicable_roles`](infoschema-applicable-roles.md)
- **application time** — [Application Time](ddl-temporal-tables.md#ddl-application-time)
- **application_name configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **arbitrary precision numbers** — [Arbitrary Precision Numbers](datatype-numeric.md#datatype-numeric-decimal)
- **Archive Modules** — [Archive Modules](archive-modules.md)
- **archive_cleanup_command configuration parameter** — [Archive Recovery](runtime-config-wal.md#runtime-config-wal-archive-recovery)
- **archive_command configuration parameter** — [Archiving](runtime-config-wal.md#runtime-config-wal-archiving)
- **archive_library configuration parameter** — [Archiving](runtime-config-wal.md#runtime-config-wal-archiving)
- **archive_mode configuration parameter** — [Archiving](runtime-config-wal.md#runtime-config-wal-archiving)
- **archive_timeout configuration parameter** — [Archiving](runtime-config-wal.md#runtime-config-wal-archiving)
- **area** — [Geometric Functions and Operators](functions-geometry.md)
- **armor** — [`armor()`, `dearmor()`](pgcrypto.md#pgcrypto-pgp-enc-funcs-armor)
- **array** — [Arrays](arrays.md)
  - accessing — [Accessing Arrays](arrays.md#arrays-accessing)
  - constant — [Array Value Input](arrays.md#arrays-input)
  - constructor — [Array Constructors](sql-expressions.md#sql-syntax-array-constructors)
  - declaration — [Declaration of Array Types](arrays.md#arrays-declaration)
  - I/O — [Array Input and Output Syntax](arrays.md#arrays-io)
  - modifying — [Modifying Arrays](arrays.md#arrays-modifying)
  - of user-defined type — [User-Defined Types](xtypes.md)
  - searching — [Searching in Arrays](arrays.md#arrays-searching)
- **ARRAY** — [Array Constructors](sql-expressions.md#sql-syntax-array-constructors)
  - determination of result type — [`UNION`, `CASE`, and Related Constructs](typeconv-union-case.md)
- **array_agg** — [Aggregate Functions](functions-aggregate.md), [Functions](intagg.md#intagg-functions)
- **array_append** — [Array Functions and Operators](functions-array.md)
- **array_cat** — [Array Functions and Operators](functions-array.md)
- **array_dims** — [Array Functions and Operators](functions-array.md)
- **array_fill** — [Array Functions and Operators](functions-array.md)
- **array_length** — [Array Functions and Operators](functions-array.md)
- **array_lower** — [Array Functions and Operators](functions-array.md)
- **array_ndims** — [Array Functions and Operators](functions-array.md)
- **array_nulls configuration parameter** — [Previous PostgreSQL Versions](runtime-config-compatible.md#runtime-config-compatible-version)
- **array_position** — [Array Functions and Operators](functions-array.md)
- **array_positions** — [Array Functions and Operators](functions-array.md)
- **array_prepend** — [Array Functions and Operators](functions-array.md)
- **array_remove** — [Array Functions and Operators](functions-array.md)
- **array_replace** — [Array Functions and Operators](functions-array.md)
- **array_reverse** — [Array Functions and Operators](functions-array.md)
- **array_sample** — [Array Functions and Operators](functions-array.md)
- **array_shuffle** — [Array Functions and Operators](functions-array.md)
- **array_sort** — [Array Functions and Operators](functions-array.md)
- **array_to_json** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **array_to_string** — [Array Functions and Operators](functions-array.md)
- **array_to_tsvector** — [Text Search Functions and Operators](functions-textsearch.md)
- **array_upper** — [Array Functions and Operators](functions-array.md)
- **ascii** — [String Functions and Operators](functions-string.md)
- **asin** — [Mathematical Functions and Operators](functions-math.md)
- **asind** — [Mathematical Functions and Operators](functions-math.md)
- **asinh** — [Mathematical Functions and Operators](functions-math.md)
- **ASSERT**
  - in PL/pgSQL — [Checking Assertions](plpgsql-errors-and-messages.md#plpgsql-statements-assert)
- **assertions**
  - in PL/pgSQL — [Checking Assertions](plpgsql-errors-and-messages.md#plpgsql-statements-assert)
- **asynchronous commit** — [Asynchronous Commit](wal-async-commit.md)
- **Asynchronous I/O** — [Glossary](glossary.md)
- **AT LOCAL** — [`AT TIME ZONE` and `AT LOCAL`](functions-datetime.md#functions-datetime-zoneconvert)
- **AT TIME ZONE** — [`AT TIME ZONE` and `AT LOCAL`](functions-datetime.md#functions-datetime-zoneconvert)
- **atan** — [Mathematical Functions and Operators](functions-math.md)
- **atan2** — [Mathematical Functions and Operators](functions-math.md)
- **atan2d** — [Mathematical Functions and Operators](functions-math.md)
- **atand** — [Mathematical Functions and Operators](functions-math.md)
- **atanh** — [Mathematical Functions and Operators](functions-math.md)
- **authentication_timeout configuration parameter** — [Authentication](runtime-config-connection.md#runtime-config-connection-authentication)
- **auth_delay** — [auth_delay — pause on authentication failure](auth-delay.md)
- **auth_delay.milliseconds configuration parameter** — [Configuration Parameters](auth-delay.md#auth-delay-configuration-parameters)
- **auto-increment** — *see* serial
- **autocommit**
  - bulk-loading data — [Disable Autocommit](populate.md#disable-autocommit)
  - psql — [Variables](app-psql.md#app-psql-variables)
- **autosummarize storage parameter** — [Index Storage Parameters](sql-createindex.md#sql-createindex-storage-parameters)
- **autovacuum**
  - general information — [The Autovacuum Daemon](routine-vacuuming.md#autovacuum)
- **autovacuum configuration parameter** — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
- **autovacuum_analyze_scale_factor**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
  - storage parameter — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_analyze_score_weight**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
- **autovacuum_analyze_threshold**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
  - storage parameter — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_enabled storage parameter** — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_freeze_max_age**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
  - storage parameter — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_freeze_min_age storage parameter** — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_freeze_score_weight**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
- **autovacuum_freeze_table_age storage parameter** — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_max_parallel_workers**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
- **autovacuum_max_workers configuration parameter** — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
- **autovacuum_multixact_freeze_max_age**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
  - storage parameter — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_multixact_freeze_min_age storage parameter** — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_multixact_freeze_score_weight**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
- **autovacuum_multixact_freeze_table_age storage parameter** — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_naptime configuration parameter** — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
- **autovacuum_parallel_workers storage parameter** — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_vacuum_cost_delay**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
  - storage parameter — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_vacuum_cost_limit**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
  - storage parameter — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_vacuum_insert_scale_factor**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
  - storage parameter — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_vacuum_insert_score_weight**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
- **autovacuum_vacuum_insert_threshold**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
  - storage parameter — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_vacuum_max_threshold**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
  - storage parameter — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_vacuum_scale_factor**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
  - storage parameter — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_vacuum_score_weight**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
- **autovacuum_vacuum_threshold**
  - configuration parameter — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
  - storage parameter — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **autovacuum_worker_slots configuration parameter** — [Automatic Vacuuming](runtime-config-vacuum.md#runtime-config-autovacuum)
- **autovacuum_work_mem configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **auto_explain** — [auto_explain — log execution plans of slow queries](auto-explain.md)
- **auto_explain.log_analyze configuration parameter** — [Configuration Parameters](auto-explain.md#auto-explain-configuration-parameters)
- **auto_explain.log_buffers configuration parameter** — [Configuration Parameters](auto-explain.md#auto-explain-configuration-parameters)
- **auto_explain.log_extension_options configuration parameter** — [Configuration Parameters](auto-explain.md#auto-explain-configuration-parameters)
- **auto_explain.log_format configuration parameter** — [Configuration Parameters](auto-explain.md#auto-explain-configuration-parameters)
- **auto_explain.log_io configuration parameter** — [Configuration Parameters](auto-explain.md#auto-explain-configuration-parameters)
- **auto_explain.log_level configuration parameter** — [Configuration Parameters](auto-explain.md#auto-explain-configuration-parameters)
- **auto_explain.log_min_duration configuration parameter** — [Configuration Parameters](auto-explain.md#auto-explain-configuration-parameters)
- **auto_explain.log_nested_statements configuration parameter** — [Configuration Parameters](auto-explain.md#auto-explain-configuration-parameters)
- **auto_explain.log_parameter_max_length configuration parameter** — [Configuration Parameters](auto-explain.md#auto-explain-configuration-parameters)
- **auto_explain.log_settings configuration parameter** — [Configuration Parameters](auto-explain.md#auto-explain-configuration-parameters)
- **auto_explain.log_timing configuration parameter** — [Configuration Parameters](auto-explain.md#auto-explain-configuration-parameters)
- **auto_explain.log_triggers configuration parameter** — [Configuration Parameters](auto-explain.md#auto-explain-configuration-parameters)
- **auto_explain.log_verbose configuration parameter** — [Configuration Parameters](auto-explain.md#auto-explain-configuration-parameters)
- **auto_explain.log_wal configuration parameter** — [Configuration Parameters](auto-explain.md#auto-explain-configuration-parameters)
- **auto_explain.sample_rate configuration parameter** — [Configuration Parameters](auto-explain.md#auto-explain-configuration-parameters)
- **avals** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **average** — [Aggregate Functions](functions-aggregate.md)
- **avg** — [Aggregate Functions](functions-aggregate.md)

## B

- **B-Tree** — *see* index
- **backend_flush_after configuration parameter** — [I/O](runtime-config-resource.md#runtime-config-resource-io)
- **Background workers** — [Background Worker Processes](bgworker.md)
- **backslash escapes** — [String Constants with C-Style Escapes](sql-syntax-lexical.md#sql-syntax-strings-escape)
- **backslash_quote configuration parameter** — [Previous PostgreSQL Versions](runtime-config-compatible.md#runtime-config-compatible-version)
- **backtrace_functions configuration parameter** — [Developer Options](runtime-config-developer.md)
- **backup** — [Backup Control Functions](functions-admin.md#functions-admin-backup), [Backup and Restore](backup.md)
- **Backup Manifest** — [Backup Manifest Format](backup-manifest-format.md)
- **base type** — [The PostgreSQL Type System](extend-type-system.md)
- **base32hex format** — [Binary String Functions and Operators](functions-binarystring.md)
- **base64 format** — [Binary String Functions and Operators](functions-binarystring.md)
- **base64url format** — [Binary String Functions and Operators](functions-binarystring.md)
- **basebackup_to_shell** — [basebackup_to_shell — example "shell" pg_basebackup module](basebackup-to-shell.md)
- **basebackup_to_shell.command configuration parameter** — [Configuration Parameters](basebackup-to-shell.md#basebackup-to-shell-configuration-parameters)
- **basebackup_to_shell.required_role configuration parameter** — [Configuration Parameters](basebackup-to-shell.md#basebackup-to-shell-configuration-parameters)
- **BASE_BACKUP** — [Streaming Replication Protocol](protocol-replication.md)
- **basic_archive** — [basic_archive — an example WAL archive module](basic-archive.md)
- **basic_archive.archive_directory configuration parameter** — [Configuration Parameters](basic-archive.md#basic-archive-configuration-parameters)
- **batch mode**
  - in libpq — [Pipeline Mode](libpq-pipeline-mode.md)
- **BEGIN** — [BEGIN](sql-begin.md)
- **BETWEEN** — [Comparison Functions and Operators](functions-comparison.md)
- **BETWEEN SYMMETRIC** — [Comparison Functions and Operators](functions-comparison.md)
- **BGWORKER_BACKEND_​DATABASE_CONNECTION** — [Background Worker Processes](bgworker.md)
- **BGWORKER_INTERRUPTIBLE** — [Background Worker Processes](bgworker.md)
- **BGWORKER_SHMEM_ACCESS** — [Background Worker Processes](bgworker.md)
- **bgwriter_delay configuration parameter** — [Background Writer](runtime-config-resource.md#runtime-config-resource-background-writer)
- **bgwriter_flush_after configuration parameter** — [Background Writer](runtime-config-resource.md#runtime-config-resource-background-writer)
- **bgwriter_lru_maxpages configuration parameter** — [Background Writer](runtime-config-resource.md#runtime-config-resource-background-writer)
- **bgwriter_lru_multiplier configuration parameter** — [Background Writer](runtime-config-resource.md#runtime-config-resource-background-writer)
- **bigint** — [Numeric Constants](sql-syntax-lexical.md#sql-syntax-constants-numeric), [Integer Types](datatype-numeric.md#datatype-int)
- **bigserial** — [Serial Types](datatype-numeric.md#datatype-serial)
- **binary data** — [Binary Data Types](datatype-binary.md)
  - functions — [Binary String Functions and Operators](functions-binarystring.md)
- **binary string**
  - concatenation — [Binary String Functions and Operators](functions-binarystring.md)
  - converting to character string — [Binary String Functions and Operators](functions-binarystring.md)
  - length — [Binary String Functions and Operators](functions-binarystring.md)
- **bison** — [Requirements](install-requirements.md)
- **bit string**
  - constant — [Bit-String Constants](sql-syntax-lexical.md#sql-syntax-bit-strings)
  - data type — [Bit String Types](datatype-bit.md)
  - length — [Bit String Functions and Operators](functions-bitstring.md)
- **bit strings**
  - functions — [Bit String Functions and Operators](functions-bitstring.md)
- **bitmap scan** — [Combining Multiple Indexes](indexes-bitmap-scans.md), [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **bit_and** — [Aggregate Functions](functions-aggregate.md)
- **bit_count** — [Binary String Functions and Operators](functions-binarystring.md), [Bit String Functions and Operators](functions-bitstring.md)
- **bit_length** — [String Functions and Operators](functions-string.md), [Binary String Functions and Operators](functions-binarystring.md), [Bit String Functions and Operators](functions-bitstring.md)
- **bit_or** — [Aggregate Functions](functions-aggregate.md)
- **bit_xor** — [Aggregate Functions](functions-aggregate.md)
- **BLOB** — *see* large object
- **block_size configuration parameter** — [Preset Options](runtime-config-preset.md)
- **bloom** — [bloom — bloom filter index access method](bloom.md)
- **bonjour configuration parameter** — [Connection Settings](runtime-config-connection.md#runtime-config-connection-settings)
- **bonjour_name configuration parameter** — [Connection Settings](runtime-config-connection.md#runtime-config-connection-settings)
- **Boolean**
  - data type — [Boolean Type](datatype-boolean.md)
  - operators — *see* operators, logical
- **bool_and** — [Aggregate Functions](functions-aggregate.md)
- **bool_or** — [Aggregate Functions](functions-aggregate.md)
- **booting**
  - starting the server during — [Starting the Database Server](server-start.md)
- **bound_box** — [Geometric Functions and Operators](functions-geometry.md)
- **box** — [Geometric Functions and Operators](functions-geometry.md)
- **box (data type)** — [Boxes](datatype-geometric.md#datatype-geometric-boxes)
- **bpchar** — [Character Types](datatype-character.md)
- **BRIN** — *see* index
- **brin_desummarize_range** — [Index Maintenance Functions](functions-admin.md#functions-admin-index)
- **brin_metapage_info** — [BRIN Functions](pageinspect.md#pageinspect-brin-funcs)
- **brin_page_items** — [BRIN Functions](pageinspect.md#pageinspect-brin-funcs)
- **brin_page_type** — [BRIN Functions](pageinspect.md#pageinspect-brin-funcs)
- **brin_revmap_data** — [BRIN Functions](pageinspect.md#pageinspect-brin-funcs)
- **brin_summarize_new_values** — [Index Maintenance Functions](functions-admin.md#functions-admin-index)
- **brin_summarize_range** — [Index Maintenance Functions](functions-admin.md#functions-admin-index)
- **broadcast** — [Network Address Functions and Operators](functions-net.md)
- **BSD Authentication** — [BSD Authentication](auth-bsd.md)
- **btree_gin** — [btree_gin — GIN operator classes with B-tree behavior](btree-gin.md)
- **btree_gist** — [btree_gist — GiST operator classes with B-tree behavior](btree-gist.md)
- **btrim** — [String Functions and Operators](functions-string.md), [Binary String Functions and Operators](functions-binarystring.md)
- **bt_index_check** — [Functions](amcheck.md#amcheck-functions)
- **bt_index_parent_check** — [Functions](amcheck.md#amcheck-functions)
- **bt_metap** — [B-Tree Functions](pageinspect.md#pageinspect-b-tree-funcs)
- **bt_multi_page_stats** — [B-Tree Functions](pageinspect.md#pageinspect-b-tree-funcs)
- **bt_page_items** — [B-Tree Functions](pageinspect.md#pageinspect-b-tree-funcs), [B-Tree Functions](pageinspect.md#pageinspect-b-tree-funcs)
- **bt_page_stats** — [B-Tree Functions](pageinspect.md#pageinspect-b-tree-funcs)
- **buffering storage parameter** — [Index Storage Parameters](sql-createindex.md#sql-createindex-storage-parameters)
- **bytea** — [Binary Data Types](datatype-binary.md)
- **bytea_output configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)

## C

- **C** — [libpq — C Library](libpq.md), [ECPG — Embedded SQL in C](ecpg.md)
- **C++** — [Using C++ for Extensibility](xfunc-c.md#extend-cpp)
- **CALL** — [CALL](sql-call.md)
- **canceling SQL queries** — [Canceling Queries in Progress](libpq-cancel.md)
- **cardinality** — [Array Functions and Operators](functions-array.md)
- **CASCADE**
  - with DROP — [Dependency Tracking](ddl-depend.md)
  - foreign key action — [Foreign Keys](ddl-constraints.md#ddl-constraints-fk)
- **Cascading Replication** — [Cascading Replication](warm-standby.md#cascading-replication)
- **CASE** — [Conditional Expressions](functions-conditional.md)
  - determination of result type — [`UNION`, `CASE`, and Related Constructs](typeconv-union-case.md)
- **case sensitivity**
  - of SQL commands — [Identifiers and Key Words](sql-syntax-lexical.md#sql-syntax-identifiers)
- **casefold** — [String Functions and Operators](functions-string.md)
- **cast**
  - I/O conversion — [Notes](sql-createcast.md#sql-createcast-notes)
- **cbrt** — [Mathematical Functions and Operators](functions-math.md)
- **ceil** — [Mathematical Functions and Operators](functions-math.md)
- **ceiling** — [Mathematical Functions and Operators](functions-math.md)
- **center** — [Geometric Functions and Operators](functions-geometry.md)
- **Certificate** — [Certificate Authentication](auth-cert.md)
- **chained transactions** — [Parameters](sql-commit.md#id-1.9.3.54.6), [Parameters](sql-rollback.md#id-1.9.3.171.6)
  - in PL/pgSQL — [Transaction Management](plpgsql-transactions.md)
- **char** — [Character Types](datatype-character.md)
- **character** — [Character Types](datatype-character.md)
- **character set** — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format), [Preset Options](runtime-config-preset.md), [Character Set Support](multibyte.md)
- **character string**
  - concatenation — [String Functions and Operators](functions-string.md)
  - constant — [String Constants](sql-syntax-lexical.md#sql-syntax-strings)
  - converting to binary string — [Binary String Functions and Operators](functions-binarystring.md)
  - data types — [Character Types](datatype-character.md)
  - length — [String Functions and Operators](functions-string.md)
  - prefix test — [String Functions and Operators](functions-string.md)
- **character varying** — [Character Types](datatype-character.md)
- **character_length** — [String Functions and Operators](functions-string.md)
- **char_length** — [String Functions and Operators](functions-string.md)
- **check constraint** — [Check Constraints](ddl-constraints.md#ddl-constraints-check-constraints)
- **CHECK OPTION** — [Parameters](sql-createview.md#id-1.9.3.99.6)
- **checkpoint** — [WAL Configuration](wal-configuration.md)
- **CHECKPOINT** — [CHECKPOINT](sql-checkpoint.md)
- **checkpoint_completion_target configuration parameter** — [Checkpoints](runtime-config-wal.md#runtime-config-wal-checkpoints)
- **checkpoint_flush_after configuration parameter** — [Checkpoints](runtime-config-wal.md#runtime-config-wal-checkpoints)
- **checkpoint_timeout configuration parameter** — [Checkpoints](runtime-config-wal.md#runtime-config-wal-checkpoints)
- **checkpoint_warning configuration parameter** — [Checkpoints](runtime-config-wal.md#runtime-config-wal-checkpoints)
- **checksums** — [Data Checksums](checksums.md)
- **check_function_bodies configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **chr** — [String Functions and Operators](functions-string.md)
- **cid** — [Object Identifier Types](datatype-oid.md)
- **cidr** — [`cidr`](datatype-net-types.md#datatype-cidr)
- **circle** — [Circles](datatype-geometric.md#datatype-circle), [Geometric Functions and Operators](functions-geometry.md)
- **citext** — [citext — a case-insensitive character string type](citext.md)
- **client authentication** — [Client Authentication](client-authentication.md)
  - timeout during — [Authentication](runtime-config-connection.md#runtime-config-connection-authentication)
- **client_connection_check_interval configuration parameter** — [TCP Settings](runtime-config-connection.md#runtime-config-tcp-settings)
- **client_encoding configuration parameter** — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)
- **client_min_messages configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **clock_timestamp** — [Date/Time Functions and Operators](functions-datetime.md)
- **CLOSE** — [CLOSE](sql-close.md)
- **cluster**
  - of databases — *see* database cluster
- **CLUSTER** — [CLUSTER](sql-cluster.md)
- **clusterdb** — [clusterdb](app-clusterdb.md)
- **clustering** — [High Availability, Load Balancing, and Replication](high-availability.md)
- **cluster_name configuration parameter** — [Process Title](runtime-config-logging.md#runtime-config-logging-proc-title)
- **cmax** — [System Columns](ddl-system-columns.md)
- **cmin** — [System Columns](ddl-system-columns.md)
- **COALESCE** — [`COALESCE`](functions-conditional.md#functions-coalesce-nvl-ifnull)
- **COLLATE** — [Collation Expressions](sql-expressions.md#sql-syntax-collate-exprs)
- **collation** — [Collation Support](collation.md)
  - in PL/pgSQL — [Collation of PL/pgSQL Variables](plpgsql-declarations.md#plpgsql-declaration-collation)
  - in SQL functions — [SQL Functions with Collations](xfunc-sql.md#xfunc-sql-collations)
- **COLLATION FOR** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **color** — [Color Support](color.md)
- **column** — [Concepts](tutorial-concepts.md), [Table Basics](ddl-basics.md)
  - adding — [Adding a Column](ddl-alter.md#ddl-alter-adding-a-column)
  - removing — [Removing a Column](ddl-alter.md#ddl-alter-removing-a-column)
  - renaming — [Renaming a Column](ddl-alter.md#ddl-alter-renaming-column)
  - system column — [System Columns](ddl-system-columns.md)
- **column data type**
  - changing — [Changing a Column's Data Type](ddl-alter.md#ddl-alter-column-type)
- **column reference** — [Column References](sql-expressions.md#sql-expressions-column-refs)
- **col_description** — [Comment Information Functions](functions-info.md#functions-info-comment)
- **comment**
  - about database objects — [Comment Information Functions](functions-info.md#functions-info-comment)
  - in SQL — [Comments](sql-syntax-lexical.md#sql-syntax-comments)
- **COMMENT** — [COMMENT](sql-comment.md)
- **COMMIT** — [COMMIT](sql-commit.md)
- **COMMIT PREPARED** — [COMMIT PREPARED](sql-commit-prepared.md)
- **commit_delay configuration parameter** — [Settings](runtime-config-wal.md#runtime-config-wal-settings)
- **commit_siblings configuration parameter** — [Settings](runtime-config-wal.md#runtime-config-wal-settings)
- **commit_timestamp_buffers configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **common table expression** — *see* WITH
- **comparison**
  - composite type — [Row and Array Comparisons](functions-comparisons.md)
  - operators — [Comparison Functions and Operators](functions-comparison.md)
  - row constructor — [Row and Array Comparisons](functions-comparisons.md)
  - subquery result row — [Single-Row Comparison](functions-subquery.md#functions-subquery-single-row-comp)
- **compiling**
  - libpq applications — [Building libpq Programs](libpq-build.md)
- **composite type** — [Composite Types](rowtypes.md), [The PostgreSQL Type System](extend-type-system.md)
  - comparison — [Row and Array Comparisons](functions-comparisons.md)
  - constant — [Constructing Composite Values](rowtypes.md#rowtypes-constructing)
  - constructor — [Row Constructors](sql-expressions.md#sql-syntax-row-constructors)
- **computed field** — [Using Composite Types in Queries](rowtypes.md#rowtypes-usage)
- **compute_query_id configuration parameter** — [Statistics Monitoring](runtime-config-statistics.md#runtime-config-statistics-monitor)
- **concat** — [String Functions and Operators](functions-string.md)
- **concat_ws** — [String Functions and Operators](functions-string.md)
- **concurrency** — [Concurrency Control](mvcc.md)
- **conditional expression** — [Conditional Expressions](functions-conditional.md)
- **configuration**
  - of recovery
    - general settings — [Recovery](runtime-config-wal.md#runtime-config-wal-recovery)
    - of a standby server — [Archive Recovery](runtime-config-wal.md#runtime-config-wal-archive-recovery)
  - of the server — [Server Configuration](runtime-config.md)
  - of the server
    - functions — [Configuration Settings Functions](functions-admin.md#functions-admin-set)
- **configure** — [Installation Procedure](install-make.md#install-procedure-make)
- **configure environment variables** — [`configure` Environment Variables](install-make.md#configure-envvars)
- **configure options** — [`configure` Options](install-make.md#configure-options)
- **config_file configuration parameter** — [File Locations](runtime-config-file-locations.md)
- **conflict**
  - schema — [The Conflict Schema](ddl-schemas.md#ddl-schemas-conflict)
- **conjunction** — [Logical Operators](functions-logical.md)
- **connectby** — [Functions Provided](tablefunc.md#tablefunc-functions-sect), [`connectby`](tablefunc.md#tablefunc-functions-connectby)
- **connection service file** — [The Connection Service File](libpq-pgservice.md)
- **conninfo** — [Connection Strings](libpq-connect.md#libpq-connstring)
- **constant** — [Constants](sql-syntax-lexical.md#sql-syntax-constants)
- **constraint** — [Constraints](ddl-constraints.md)
  - adding — [Adding a Constraint](ddl-alter.md#ddl-alter-adding-a-constraint)
  - check — [Check Constraints](ddl-constraints.md#ddl-constraints-check-constraints)
  - exclusion — [Exclusion Constraints](ddl-constraints.md#ddl-constraints-exclusion)
  - foreign key — [Foreign Keys](ddl-constraints.md#ddl-constraints-fk)
  - name — [Check Constraints](ddl-constraints.md#ddl-constraints-check-constraints)
  - NOT NULL — [Not-Null Constraints](ddl-constraints.md#ddl-constraints-not-null)
  - primary key — [Primary Keys](ddl-constraints.md#ddl-constraints-primary-keys)
  - removing — [Removing a Constraint](ddl-alter.md#ddl-alter-removing-a-constraint)
  - unique — [Unique Constraints](ddl-constraints.md#ddl-constraints-unique-constraints)
- **constraint exclusion** — [Partitioning and Constraint Exclusion](ddl-partitioning.md#ddl-partitioning-constraint-exclusion), [Other Planner Options](runtime-config-query.md#runtime-config-query-other)
- **constraint_exclusion configuration parameter** — [Other Planner Options](runtime-config-query.md#runtime-config-query-other)
- **container type** — [The PostgreSQL Type System](extend-type-system.md)
- **CONTINUE**
  - in PL/pgSQL — [`CONTINUE`](plpgsql-control-structures.md#plpgsql-control-structures-loops-continue)
- **continuous archiving** — [Continuous Archiving and Point-in-Time Recovery (PITR)](continuous-archiving.md)
  - in standby — [Continuous Archiving in Standby](warm-standby.md#continuous-archiving-in-standby)
- **control file** — [Extension Files](extend-extensions.md#extend-extensions-files)
- **convert** — [Binary String Functions and Operators](functions-binarystring.md)
- **convert_from** — [Binary String Functions and Operators](functions-binarystring.md)
- **convert_to** — [Binary String Functions and Operators](functions-binarystring.md)
- **COPY** — [Populating a Table With Rows](tutorial-populate.md), [COPY](sql-copy.md)
  - with libpq — [Functions Associated with the `COPY` Command](libpq-copy.md)
- **corr** — [Aggregate Functions](functions-aggregate.md)
- **correlation** — [Aggregate Functions](functions-aggregate.md)
  - in the query planner — [Extended Statistics](planner-stats.md#planner-stats-extended)
- **cos** — [Mathematical Functions and Operators](functions-math.md)
- **cosd** — [Mathematical Functions and Operators](functions-math.md)
- **cosh** — [Mathematical Functions and Operators](functions-math.md)
- **cot** — [Mathematical Functions and Operators](functions-math.md)
- **cotd** — [Mathematical Functions and Operators](functions-math.md)
- **count** — [Aggregate Functions](functions-aggregate.md)
- **covariance**
  - population — [Aggregate Functions](functions-aggregate.md)
  - sample — [Aggregate Functions](functions-aggregate.md)
- **covar_pop** — [Aggregate Functions](functions-aggregate.md)
- **covar_samp** — [Aggregate Functions](functions-aggregate.md)
- **covering index** — [Index-Only Scans and Covering Indexes](indexes-index-only-scans.md)
- **cpu_index_tuple_cost configuration parameter** — [Planner Cost Constants](runtime-config-query.md#runtime-config-query-constants)
- **cpu_operator_cost configuration parameter** — [Planner Cost Constants](runtime-config-query.md#runtime-config-query-constants)
- **cpu_tuple_cost configuration parameter** — [Planner Cost Constants](runtime-config-query.md#runtime-config-query-constants)
- **crc32** — [Binary String Functions and Operators](functions-binarystring.md)
- **crc32c** — [Binary String Functions and Operators](functions-binarystring.md)
- **CREATE ACCESS METHOD** — [CREATE ACCESS METHOD](sql-create-access-method.md)
- **CREATE AGGREGATE** — [CREATE AGGREGATE](sql-createaggregate.md)
- **CREATE CAST** — [CREATE CAST](sql-createcast.md)
- **CREATE COLLATION** — [CREATE COLLATION](sql-createcollation.md)
- **CREATE CONVERSION** — [CREATE CONVERSION](sql-createconversion.md)
- **CREATE DATABASE** — [Creating a Database](manage-ag-createdb.md), [CREATE DATABASE](sql-createdatabase.md)
- **CREATE DOMAIN** — [CREATE DOMAIN](sql-createdomain.md)
- **CREATE EVENT TRIGGER** — [CREATE EVENT TRIGGER](sql-createeventtrigger.md)
- **CREATE EXTENSION** — [CREATE EXTENSION](sql-createextension.md)
- **CREATE FOREIGN DATA WRAPPER** — [CREATE FOREIGN DATA WRAPPER](sql-createforeigndatawrapper.md)
- **CREATE FOREIGN TABLE** — [CREATE FOREIGN TABLE](sql-createforeigntable.md)
- **CREATE FUNCTION** — [CREATE FUNCTION](sql-createfunction.md)
- **CREATE GROUP** — [CREATE GROUP](sql-creategroup.md)
- **CREATE INDEX** — [CREATE INDEX](sql-createindex.md)
- **CREATE LANGUAGE** — [CREATE LANGUAGE](sql-createlanguage.md)
- **CREATE MATERIALIZED VIEW** — [CREATE MATERIALIZED VIEW](sql-creatematerializedview.md)
- **CREATE OPERATOR** — [CREATE OPERATOR](sql-createoperator.md)
- **CREATE OPERATOR CLASS** — [CREATE OPERATOR CLASS](sql-createopclass.md)
- **CREATE OPERATOR FAMILY** — [CREATE OPERATOR FAMILY](sql-createopfamily.md)
- **CREATE POLICY** — [CREATE POLICY](sql-createpolicy.md)
- **CREATE PROCEDURE** — [CREATE PROCEDURE](sql-createprocedure.md)
- **CREATE PROPERTY GRAPH** — [CREATE PROPERTY GRAPH](sql-create-property-graph.md)
- **CREATE PUBLICATION** — [CREATE PUBLICATION](sql-createpublication.md)
- **CREATE ROLE** — [Database Roles](database-roles.md), [CREATE ROLE](sql-createrole.md)
- **CREATE RULE** — [CREATE RULE](sql-createrule.md)
- **CREATE SCHEMA** — [CREATE SCHEMA](sql-createschema.md)
- **CREATE SEQUENCE** — [CREATE SEQUENCE](sql-createsequence.md)
- **CREATE SERVER** — [CREATE SERVER](sql-createserver.md)
- **CREATE STATISTICS** — [CREATE STATISTICS](sql-createstatistics.md)
- **CREATE SUBSCRIPTION** — [CREATE SUBSCRIPTION](sql-createsubscription.md)
- **CREATE TABLE** — [Creating a New Table](tutorial-table.md), [CREATE TABLE](sql-createtable.md)
- **CREATE TABLE AS** — [CREATE TABLE AS](sql-createtableas.md)
- **CREATE TABLESPACE** — [Tablespaces](manage-ag-tablespaces.md), [CREATE TABLESPACE](sql-createtablespace.md)
- **CREATE TEXT SEARCH CONFIGURATION** — [CREATE TEXT SEARCH CONFIGURATION](sql-createtsconfig.md)
- **CREATE TEXT SEARCH DICTIONARY** — [CREATE TEXT SEARCH DICTIONARY](sql-createtsdictionary.md)
- **CREATE TEXT SEARCH PARSER** — [CREATE TEXT SEARCH PARSER](sql-createtsparser.md)
- **CREATE TEXT SEARCH TEMPLATE** — [CREATE TEXT SEARCH TEMPLATE](sql-createtstemplate.md)
- **CREATE TRANSFORM** — [CREATE TRANSFORM](sql-createtransform.md)
- **CREATE TRIGGER** — [CREATE TRIGGER](sql-createtrigger.md)
- **CREATE TYPE** — [CREATE TYPE](sql-createtype.md)
- **CREATE USER** — [CREATE USER](sql-createuser.md)
- **CREATE USER MAPPING** — [CREATE USER MAPPING](sql-createusermapping.md)
- **CREATE VIEW** — [CREATE VIEW](sql-createview.md)
- **createdb** — [Creating a Database](tutorial-createdb.md), [Creating a Database](manage-ag-createdb.md), [createdb](app-createdb.md)
- **createrole_self_grant**
  - configuration parameter — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **createrole_self_grant configuration parameter**
  - use in securing functions — [Writing `SECURITY DEFINER` Functions Safely](sql-createfunction.md#sql-createfunction-security)
- **createuser** — [Database Roles](database-roles.md), [createuser](app-createuser.md)
- **CREATE_REPLICATION_SLOT** — [Streaming Replication Protocol](protocol-replication.md)
- **cross compilation** — [Build Process Details](install-make.md#configure-options-build-process), [Build Process Details](install-meson.md#meson-options-build-process)
- **cross join** — [Joined Tables](queries-table-expressions.md#queries-join)
- **crosstab** — [`crosstab(text)`](tablefunc.md#tablefunc-functions-crosstab-text), [`crosstabN(text)`](tablefunc.md#tablefunc-functions-crosstab-n-text), [`crosstab(text, text)`](tablefunc.md#tablefunc-functions-crosstab-text-2)
- **crypt** — [`crypt()`](pgcrypto.md#pgcrypto-password-hashing-funcs-crypt)
- **cstring** — [Pseudo-Types](datatype-pseudo.md)
- **CSV (Comma-Separated Values) format**
  - in psql — [Meta-Commands](app-psql.md#app-psql-meta-commands)
- **ctid** — [System Columns](ddl-system-columns.md)
- **CTID** — [View Rules in Non-`SELECT` Statements](rules-views.md#rules-views-non-select)
- **CUBE** — [`GROUPING SETS`, `CUBE`, and `ROLLUP`](queries-table-expressions.md#queries-grouping-sets)
- **cube (extension)** — [cube — a multi-dimensional cube data type](cube.md)
- **cume_dist** — [Window Functions](functions-window.md)
  - hypothetical — [Aggregate Functions](functions-aggregate.md)
- **current_catalog** — [Session Information Functions](functions-info.md#functions-info-session)
- **current_database** — [Session Information Functions](functions-info.md#functions-info-session)
- **current_date** — [Date/Time Functions and Operators](functions-datetime.md)
- **current_logfiles**
  - and the log_destination configuration parameter — [Where to Log](runtime-config-logging.md#runtime-config-logging-where)
  - and the pg_current_logfile function — [Session Information Functions](functions-info.md#functions-info-session)
- **current_query** — [Session Information Functions](functions-info.md#functions-info-session)
- **current_role** — [Session Information Functions](functions-info.md#functions-info-session)
- **current_schema** — [Session Information Functions](functions-info.md#functions-info-session)
- **current_schemas** — [Session Information Functions](functions-info.md#functions-info-session)
- **current_setting** — [Configuration Settings Functions](functions-admin.md#functions-admin-set)
- **current_time** — [Date/Time Functions and Operators](functions-datetime.md)
- **current_timestamp** — [Date/Time Functions and Operators](functions-datetime.md)
- **current_user** — [Session Information Functions](functions-info.md#functions-info-session)
- **currval** — [Sequence Manipulation Functions](functions-sequence.md)
- **cursor**
  - CLOSE — [CLOSE](sql-close.md)
  - DECLARE — [DECLARE](sql-declare.md)
  - FETCH — [FETCH](sql-fetch.md)
  - in PL/pgSQL — [Cursors](plpgsql-cursors.md)
  - MOVE — [MOVE](sql-move.md)
  - showing the query plan — [EXPLAIN](sql-explain.md)
- **cursor_tuple_fraction configuration parameter** — [Other Planner Options](runtime-config-query.md#runtime-config-query-other)
- **custom scan provider**
  - handler for — [Writing a Custom Scan Provider](custom-scan.md)
- **Cygwin**
  - installation on — [Cygwin](installation-platform-notes.md#installation-notes-cygwin)

## D

- **daitch_mokotoff** — [Daitch-Mokotoff Soundex](fuzzystrmatch.md#fuzzystrmatch-daitch-mokotoff)
- **data area** — *see* database cluster
- **data partitioning** — [High Availability, Load Balancing, and Replication](high-availability.md)
- **data type** — [Data Types](datatype.md)
  - base — [The PostgreSQL Type System](extend-type-system.md)
  - category — [Overview](typeconv-overview.md)
  - composite — [The PostgreSQL Type System](extend-type-system.md)
  - constant — [Constants of Other Types](sql-syntax-lexical.md#sql-syntax-constants-generic)
  - container — [The PostgreSQL Type System](extend-type-system.md)
  - conversion — [Type Conversion](typeconv.md)
  - domain — [Domain Types](domains.md)
  - enumerated (enum) — [Enumerated Types](datatype-enum.md)
  - internal organization — [Base Types in C-Language Functions](xfunc-c.md#xfunc-c-basetype)
  - numeric — [Numeric Types](datatype-numeric.md)
  - polymorphic — [Polymorphic Types](extend-type-system.md#extend-types-polymorphic)
  - type cast — [Type Casts](sql-expressions.md#sql-syntax-type-casts)
  - user-defined — [User-Defined Types](xtypes.md)
- **database** — [Managing Databases](managing-databases.md)
  - creating — [Creating a Database](tutorial-createdb.md)
  - privilege to create — [Role Attributes](role-attributes.md)
- **database activity**
  - monitoring — [Monitoring Database Activity](monitoring.md)
- **database cluster** — [Concepts](tutorial-concepts.md), [Creating a Database Cluster](creating-cluster.md)
- **data_checksums configuration parameter** — [Preset Options](runtime-config-preset.md)
- **data_directory configuration parameter** — [File Locations](runtime-config-file-locations.md)
- **data_directory_mode configuration parameter** — [Preset Options](runtime-config-preset.md)
- **data_sync_retry configuration parameter** — [Error Handling](runtime-config-error-handling.md)
- **date** — [Date/Time Types](datatype-datetime.md), [Dates](datatype-datetime.md#datatype-datetime-input-dates)
  - constants — [Special Values](datatype-datetime.md#datatype-datetime-special-values)
  - current — [Current Date/Time](functions-datetime.md#functions-datetime-current)
  - output format — [Date/Time Output](datatype-datetime.md#datatype-datetime-output); *see also* formatting
- **DateStyle configuration parameter** — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)
- **date_add** — [Date/Time Functions and Operators](functions-datetime.md)
- **date_bin** — [`date_bin`](functions-datetime.md#functions-datetime-bin)
- **date_part** — [Date/Time Functions and Operators](functions-datetime.md), [`EXTRACT`, `date_part`](functions-datetime.md#functions-datetime-extract)
- **date_subtract** — [Date/Time Functions and Operators](functions-datetime.md)
- **date_trunc** — [Date/Time Functions and Operators](functions-datetime.md), [`date_trunc`](functions-datetime.md#functions-datetime-trunc)
- **dblink** — [dblink — connect to other PostgreSQL databases](dblink.md), [dblink](contrib-dblink-function.md)
- **dblink_build_sql_delete** — [dblink_build_sql_delete](contrib-dblink-build-sql-delete.md)
- **dblink_build_sql_insert** — [dblink_build_sql_insert](contrib-dblink-build-sql-insert.md)
- **dblink_build_sql_update** — [dblink_build_sql_update](contrib-dblink-build-sql-update.md)
- **dblink_cancel_query** — [dblink_cancel_query](contrib-dblink-cancel-query.md)
- **dblink_close** — [dblink_close](contrib-dblink-close.md)
- **dblink_connect** — [dblink_connect](contrib-dblink-connect.md)
- **dblink_connect_u** — [dblink_connect_u](contrib-dblink-connect-u.md)
- **dblink_disconnect** — [dblink_disconnect](contrib-dblink-disconnect.md)
- **dblink_error_message** — [dblink_error_message](contrib-dblink-error-message.md)
- **dblink_exec** — [dblink_exec](contrib-dblink-exec.md)
- **dblink_fetch** — [dblink_fetch](contrib-dblink-fetch.md)
- **dblink_get_connections** — [dblink_get_connections](contrib-dblink-get-connections.md)
- **dblink_get_notify** — [dblink_get_notify](contrib-dblink-get-notify.md)
- **dblink_get_pkey** — [dblink_get_pkey](contrib-dblink-get-pkey.md)
- **dblink_get_result** — [dblink_get_result](contrib-dblink-get-result.md)
- **dblink_is_busy** — [dblink_is_busy](contrib-dblink-is-busy.md)
- **dblink_open** — [dblink_open](contrib-dblink-open.md)
- **dblink_send_query** — [dblink_send_query](contrib-dblink-send-query.md)
- **deadlock** — [Deadlocks](explicit-locking.md#locking-deadlocks)
  - timeout during — [Lock Management](runtime-config-locks.md)
- **deadlock_timeout configuration parameter** — [Lock Management](runtime-config-locks.md)
- **DEALLOCATE** — [DEALLOCATE](sql-deallocate.md)
- **dearmor** — [`armor()`, `dearmor()`](pgcrypto.md#pgcrypto-pgp-enc-funcs-armor)
- **debug_assertions configuration parameter** — [Preset Options](runtime-config-preset.md)
- **debug_copy_parse_plan_trees configuration parameter** — [Developer Options](runtime-config-developer.md)
- **debug_deadlocks configuration parameter** — [Developer Options](runtime-config-developer.md)
- **debug_discard_caches configuration parameter** — [Developer Options](runtime-config-developer.md)
- **debug_exec_backend configuration parameter** — [Preset Options](runtime-config-preset.md)
- **debug_io_direct configuration parameter** — [Developer Options](runtime-config-developer.md)
- **debug_logical_replication_streaming configuration parameter** — [Developer Options](runtime-config-developer.md)
- **debug_parallel_query configuration parameter** — [Developer Options](runtime-config-developer.md)
- **debug_pretty_print configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **debug_print_parse configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **debug_print_plan configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **debug_print_raw_parse configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **debug_print_rewritten configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **debug_raw_expression_coverage_test configuration parameter** — [Developer Options](runtime-config-developer.md)
- **debug_write_read_parse_plan_trees configuration parameter** — [Developer Options](runtime-config-developer.md)
- **decimal** — *see* numeric
- **DECLARE** — [DECLARE](sql-declare.md)
- **decode** — [Binary String Functions and Operators](functions-binarystring.md)
- **decode_bytea**
  - in PL/Perl — [Utility Functions in PL/Perl](plperl-builtins.md#plperl-utility-functions)
- **decrypt** — [Raw Encryption Functions](pgcrypto.md#pgcrypto-raw-enc-funcs)
- **decrypt_iv** — [Raw Encryption Functions](pgcrypto.md#pgcrypto-raw-enc-funcs)
- **deduplicate_items storage parameter** — [Index Storage Parameters](sql-createindex.md#sql-createindex-storage-parameters)
- **default value** — [Default Values](ddl-default.md)
  - changing — [Changing a Column's Default Value](ddl-alter.md#ddl-alter-column-default)
- **default-roles** — [Default Roles Renamed to Predefined Roles](default-roles.md)
- **default_statistics_target configuration parameter** — [Other Planner Options](runtime-config-query.md#runtime-config-query-other)
- **default_tablespace configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **default_table_access_method configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **default_text_search_config configuration parameter** — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)
- **default_toast_compression configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **default_transaction_deferrable configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **default_transaction_isolation configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **default_transaction_read_only configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **deferrable transaction** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
  - setting — [SET TRANSACTION](sql-set-transaction.md)
  - setting default — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **defined** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **degrees** — [Mathematical Functions and Operators](functions-math.md)
- **delay** — [Delaying Execution](functions-datetime.md#functions-datetime-delay)
- **DELETE** — [Deletions](tutorial-delete.md), [Deleting Data](dml-delete.md), [DELETE](sql-delete.md)
  - RETURNING — [Returning Data from Modified Rows](dml-returning.md)
- **delete** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **deleting** — [Deleting Data](dml-delete.md)
- **dense_rank** — [Window Functions](functions-window.md)
  - hypothetical — [Aggregate Functions](functions-aggregate.md)
- **diagonal** — [Geometric Functions and Operators](functions-geometry.md)
- **diameter** — [Geometric Functions and Operators](functions-geometry.md)
- **dict_int** — [dict_int — example full-text search dictionary for integers](dict-int.md)
- **dict_xsyn** — [dict_xsyn — example synonym full-text search dictionary](dict-xsyn.md)
- **difference** — [Soundex](fuzzystrmatch.md#fuzzystrmatch-soundex)
- **digest** — [`digest()`](pgcrypto.md#pgcrypto-general-hashing-funcs-digest)
- **dirty read** — [Transaction Isolation](transaction-iso.md)
- **DISCARD** — [DISCARD](sql-discard.md)
- **disjunction** — [Logical Operators](functions-logical.md)
- **disk drive** — [WAL Internals](wal-internals.md)
- **disk space** — [Recovering Disk Space](routine-vacuuming.md#vacuum-for-space-recovery)
- **disk usage** — [Determining Disk Usage](diskusage.md#disk-usage)
- **DISTINCT** — [Querying a Table](tutorial-select.md)
  - GROUP BY DISTINCT — [`GROUPING SETS`, `CUBE`, and `ROLLUP`](queries-table-expressions.md#queries-grouping-sets)
  - SELECT DISTINCT — [`DISTINCT`](queries-select-lists.md#queries-distinct)
- **div** — [Mathematical Functions and Operators](functions-math.md)
- **dmetaphone** — [Double Metaphone](fuzzystrmatch.md#fuzzystrmatch-double-metaphone)
- **dmetaphone_alt** — [Double Metaphone](fuzzystrmatch.md#fuzzystrmatch-double-metaphone)
- **DO** — [DO](sql-do.md)
- **document**
  - text search — [What Is a Document?](textsearch-intro.md#textsearch-document)
- **dollar quoting** — [Dollar-Quoted String Constants](sql-syntax-lexical.md#sql-syntax-dollar-quoting)
- **domain** — [Domain Types](domains.md)
- **double precision** — [Floating-Point Types](datatype-numeric.md#datatype-float)
- **DROP ACCESS METHOD** — [DROP ACCESS METHOD](sql-drop-access-method.md)
- **DROP AGGREGATE** — [DROP AGGREGATE](sql-dropaggregate.md)
- **DROP CAST** — [DROP CAST](sql-dropcast.md)
- **DROP COLLATION** — [DROP COLLATION](sql-dropcollation.md)
- **DROP CONVERSION** — [DROP CONVERSION](sql-dropconversion.md)
- **DROP DATABASE** — [Destroying a Database](manage-ag-dropdb.md), [DROP DATABASE](sql-dropdatabase.md)
- **DROP DOMAIN** — [DROP DOMAIN](sql-dropdomain.md)
- **DROP EVENT TRIGGER** — [DROP EVENT TRIGGER](sql-dropeventtrigger.md)
- **DROP EXTENSION** — [DROP EXTENSION](sql-dropextension.md)
- **DROP FOREIGN DATA WRAPPER** — [DROP FOREIGN DATA WRAPPER](sql-dropforeigndatawrapper.md)
- **DROP FOREIGN TABLE** — [DROP FOREIGN TABLE](sql-dropforeigntable.md)
- **DROP FUNCTION** — [DROP FUNCTION](sql-dropfunction.md)
- **DROP GROUP** — [DROP GROUP](sql-dropgroup.md)
- **DROP INDEX** — [DROP INDEX](sql-dropindex.md)
- **DROP LANGUAGE** — [DROP LANGUAGE](sql-droplanguage.md)
- **DROP MATERIALIZED VIEW** — [DROP MATERIALIZED VIEW](sql-dropmaterializedview.md)
- **DROP OPERATOR** — [DROP OPERATOR](sql-dropoperator.md)
- **DROP OPERATOR CLASS** — [DROP OPERATOR CLASS](sql-dropopclass.md)
- **DROP OPERATOR FAMILY** — [DROP OPERATOR FAMILY](sql-dropopfamily.md)
- **DROP OWNED** — [DROP OWNED](sql-drop-owned.md)
- **DROP POLICY** — [DROP POLICY](sql-droppolicy.md)
- **DROP PROCEDURE** — [DROP PROCEDURE](sql-dropprocedure.md)
- **DROP PROPERTY GRAPH** — [DROP PROPERTY GRAPH](sql-drop-property-graph.md)
- **DROP PUBLICATION** — [DROP PUBLICATION](sql-droppublication.md)
- **DROP ROLE** — [Database Roles](database-roles.md), [DROP ROLE](sql-droprole.md)
- **DROP ROUTINE** — [DROP ROUTINE](sql-droproutine.md)
- **DROP RULE** — [DROP RULE](sql-droprule.md)
- **DROP SCHEMA** — [DROP SCHEMA](sql-dropschema.md)
- **DROP SEQUENCE** — [DROP SEQUENCE](sql-dropsequence.md)
- **DROP SERVER** — [DROP SERVER](sql-dropserver.md)
- **DROP STATISTICS** — [DROP STATISTICS](sql-dropstatistics.md)
- **DROP SUBSCRIPTION** — [DROP SUBSCRIPTION](sql-dropsubscription.md)
- **DROP TABLE** — [Creating a New Table](tutorial-table.md), [DROP TABLE](sql-droptable.md)
- **DROP TABLESPACE** — [DROP TABLESPACE](sql-droptablespace.md)
- **DROP TEXT SEARCH CONFIGURATION** — [DROP TEXT SEARCH CONFIGURATION](sql-droptsconfig.md)
- **DROP TEXT SEARCH DICTIONARY** — [DROP TEXT SEARCH DICTIONARY](sql-droptsdictionary.md)
- **DROP TEXT SEARCH PARSER** — [DROP TEXT SEARCH PARSER](sql-droptsparser.md)
- **DROP TEXT SEARCH TEMPLATE** — [DROP TEXT SEARCH TEMPLATE](sql-droptstemplate.md)
- **DROP TRANSFORM** — [DROP TRANSFORM](sql-droptransform.md)
- **DROP TRIGGER** — [DROP TRIGGER](sql-droptrigger.md)
- **DROP TYPE** — [DROP TYPE](sql-droptype.md)
- **DROP USER** — [DROP USER](sql-dropuser.md)
- **DROP USER MAPPING** — [DROP USER MAPPING](sql-dropusermapping.md)
- **DROP VIEW** — [DROP VIEW](sql-dropview.md)
- **dropdb** — [Destroying a Database](manage-ag-dropdb.md), [dropdb](app-dropdb.md)
- **dropuser** — [Database Roles](database-roles.md), [dropuser](app-dropuser.md)
- **DROP_REPLICATION_SLOT** — [Streaming Replication Protocol](protocol-replication.md)
- **DTD** — [Creating XML Values](datatype-xml.md#datatype-xml-creating)
- **DTrace** — [Developer Options](install-make.md#configure-options-devel), [Developer Options](install-meson.md#meson-options-devel), [Dynamic Tracing](dynamic-trace.md)
- **duplicate** — [Querying a Table](tutorial-select.md)
- **duplicates** — [`DISTINCT`](queries-select-lists.md#queries-distinct)
- **dynamic loading** — [Other Defaults](runtime-config-client.md#runtime-config-client-other), [Dynamic Loading](xfunc-c.md#xfunc-c-dynload)
- **dynamic_library_path** — [Dynamic Loading](xfunc-c.md#xfunc-c-dynload)
- **dynamic_library_path configuration parameter** — [Other Defaults](runtime-config-client.md#runtime-config-client-other)
- **dynamic_shared_memory_type configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)

## E

- **each** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **earth** — [Cube-Based Earth Distances](earthdistance.md#earthdistance-cube-based)
- **earthdistance** — [earthdistance — calculate great-circle distances](earthdistance.md)
- **earth_box** — [Cube-Based Earth Distances](earthdistance.md#earthdistance-cube-based)
- **earth_distance** — [Cube-Based Earth Distances](earthdistance.md#earthdistance-cube-based)
- **ECPG** — [ECPG — Embedded SQL in C](ecpg.md)
- **ecpg** — [ecpg](app-ecpg.md)
- **effective_cache_size configuration parameter** — [Planner Cost Constants](runtime-config-query.md#runtime-config-query-constants)
- **effective_io_concurrency configuration parameter** — [I/O](runtime-config-resource.md#runtime-config-resource-io)
- **effective_wal_level configuration parameter** — [Preset Options](runtime-config-preset.md)
- **elog** — [Reporting Errors Within the Server](error-message-reporting.md)
  - in PL/Perl — [Utility Functions in PL/Perl](plperl-builtins.md#plperl-utility-functions)
  - in PL/Python — [Utility Functions](plpython-util.md)
  - in PL/Tcl — [Database Access from PL/Tcl](pltcl-dbaccess.md)
- **embedded SQL**
  - in C — [ECPG — Embedded SQL in C](ecpg.md)
- **enabled role** — [`enabled_roles`](infoschema-enabled-roles.md)
- **enable_async_append configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_bitmapscan configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_distinct_reordering configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_eager_aggregate configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_gathermerge configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_groupagg configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_group_by_reordering configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_hashagg configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_hashjoin configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_incremental_sort configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_indexonlyscan configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_indexscan configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_material configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_memoize configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_mergejoin configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_nestloop configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_parallel_append configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_parallel_hash configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_partitionwise_aggregate configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_partitionwise_join configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_partition_pruning configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_presorted_aggregate configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_self_join_elimination configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_seqscan configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_sort configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **enable_tidscan configuration parameter** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **encode** — [Binary String Functions and Operators](functions-binarystring.md)
- **encode_array_constructor**
  - in PL/Perl — [Utility Functions in PL/Perl](plperl-builtins.md#plperl-utility-functions)
- **encode_array_literal**
  - in PL/Perl — [Utility Functions in PL/Perl](plperl-builtins.md#plperl-utility-functions)
- **encode_bytea**
  - in PL/Perl — [Utility Functions in PL/Perl](plperl-builtins.md#plperl-utility-functions)
- **encode_typed_literal**
  - in PL/Perl — [Utility Functions in PL/Perl](plperl-builtins.md#plperl-utility-functions)
- **encrypt** — [Raw Encryption Functions](pgcrypto.md#pgcrypto-raw-enc-funcs)
- **encryption** — [Encryption Options](encryption-options.md)
  - for specific columns — [pgcrypto — cryptographic functions](pgcrypto.md)
- **encrypt_iv** — [Raw Encryption Functions](pgcrypto.md#pgcrypto-raw-enc-funcs)
- **END** — [END](sql-end.md)
- **enumerated types** — [Enumerated Types](datatype-enum.md)
- **enum_first** — [Enum Support Functions](functions-enum.md)
- **enum_last** — [Enum Support Functions](functions-enum.md)
- **enum_range** — [Enum Support Functions](functions-enum.md)
- **environment variable** — [Environment Variables](libpq-envars.md)
- **ephemeral named relation**
  - registering with SPI — [SPI_register_relation](spi-spi-register-relation.md), [SPI_register_trigger_data](spi-spi-register-trigger-data.md)
  - unregistering from SPI — [SPI_unregister_relation](spi-spi-unregister-relation.md)
- **ereport** — [Reporting Errors Within the Server](error-message-reporting.md)
- **erf** — [Mathematical Functions and Operators](functions-math.md)
- **erfc** — [Mathematical Functions and Operators](functions-math.md)
- **error codes**
  - libpq — [Main Functions](libpq-exec.md#libpq-exec-main)
  - list of — [PostgreSQL Error Codes](errcodes-appendix.md)
- **error message**
  - in PGcancelConn — [Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-functions)
  - in PGconn — [Connection Status Functions](libpq-status.md)
- **error_on_null** — [Comparison Functions and Operators](functions-comparison.md)
- **escape format** — [Binary String Functions and Operators](functions-binarystring.md)
- **escape string syntax** — [String Constants with C-Style Escapes](sql-syntax-lexical.md#sql-syntax-strings-escape)
- **escaping strings**
  - in libpq — [Escaping Strings for Inclusion in SQL Commands](libpq-exec.md#libpq-exec-escape-string)
- **event log**
  - event log — [Registering Event Log on Windows](event-log-registration.md)
- **event trigger** — [Event Triggers](event-triggers.md)
  - in C — [Writing Event Trigger Functions in C](event-trigger-interface.md)
  - in PL/Python — [Event Trigger Functions](plpython-event-trigger.md)
  - in PL/Tcl — [Event Trigger Functions in PL/Tcl](pltcl-event-trigger.md)
- **event_source configuration parameter** — [Where to Log](runtime-config-logging.md#runtime-config-logging-where)
- **event_trigger** — [Pseudo-Types](datatype-pseudo.md)
- **event_triggers**
  - configuration parameter — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **every** — [Aggregate Functions](functions-aggregate.md)
- **EXCEPT** — [Combining Queries (`UNION`, `INTERSECT`, `EXCEPT`)](queries-union.md)
- **exceptions**
  - in PL/pgSQL — [Trapping Errors](plpgsql-control-structures.md#plpgsql-error-trapping)
  - in PL/Tcl — [Error Handling in PL/Tcl](pltcl-error-handling.md)
- **exclusion constraint** — [Exclusion Constraints](ddl-constraints.md#ddl-constraints-exclusion)
- **EXECUTE** — [EXECUTE](sql-execute.md)
- **exist** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **EXISTS** — [Subquery Expressions](functions-subquery.md)
- **EXIT**
  - in PL/pgSQL — [`EXIT`](plpgsql-control-structures.md#plpgsql-control-structures-loops-exit)
- **exit_on_error configuration parameter** — [Error Handling](runtime-config-error-handling.md)
- **exp** — [Mathematical Functions and Operators](functions-math.md)
- **EXPLAIN** — [Using `EXPLAIN`](using-explain.md), [EXPLAIN](sql-explain.md)
- **expression**
  - order of evaluation — [Expression Evaluation Rules](sql-expressions.md#syntax-express-eval)
  - syntax — [Value Expressions](sql-expressions.md)
- **extending SQL** — [Extending SQL](extend.md)
- **extension** — [Packaging Related Objects into an Extension](extend-extensions.md)
  - externally maintained — [Extensions](external-extensions.md)
- **extension_control_path configuration parameter** — [Other Defaults](runtime-config-client.md#runtime-config-client-other)
- **external_pid_file configuration parameter** — [File Locations](runtime-config-file-locations.md)
- **extract** — [Date/Time Functions and Operators](functions-datetime.md), [`EXTRACT`, `date_part`](functions-datetime.md#functions-datetime-extract)
- **extra_float_digits configuration parameter** — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)

## F

- **factorial** — [Mathematical Functions and Operators](functions-math.md)
- **failover** — [High Availability, Load Balancing, and Replication](high-availability.md)
- **false** — [Boolean Type](datatype-boolean.md)
- **family** — [Network Address Functions and Operators](functions-net.md)
- **fast path** — [The Fast-Path Interface](libpq-fastpath.md)
- **fast-path locking** — [Fast-Path Locking](explicit-locking.md#locking-tables-fast-path)
- **fastupdate storage parameter** — [Index Storage Parameters](sql-createindex.md#sql-createindex-storage-parameters)
- **fdw_handler** — [Pseudo-Types](datatype-pseudo.md)
- **FETCH** — [FETCH](sql-fetch.md)
- **field**
  - computed — [Using Composite Types in Queries](rowtypes.md#rowtypes-usage)
- **field selection** — [Field Selection](sql-expressions.md#field-selection)
- **file system mount points** — [Use of Secondary File Systems](creating-cluster.md#creating-cluster-mount-points)
- **file_copy_method configuration parameter** — [Disk](runtime-config-resource.md#runtime-config-resource-disk)
- **file_extend_method configuration parameter** — [Disk](runtime-config-resource.md#runtime-config-resource-disk)
- **file_fdw** — [file_fdw — access data files in the server's file system](file-fdw.md)
- **fillfactor storage parameter** — [Index Storage Parameters](sql-createindex.md#sql-createindex-storage-parameters), [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **FILTER** — [Aggregate Expressions](sql-expressions.md#syntax-aggregates)
- **fips_mode** — [OpenSSL Support Functions](pgcrypto.md#pgcrypto-openssl-support-funcs)
- **first_value** — [Window Functions](functions-window.md)
- **flex** — [Requirements](install-requirements.md)
- **float4** — *see* real
- **float8** — *see* double precision
- **floating point** — [Floating-Point Types](datatype-numeric.md#datatype-float)
- **floating-point**
  - display — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)
- **floor** — [Mathematical Functions and Operators](functions-math.md)
- **foreign data** — [Foreign Data](ddl-foreign-data.md)
- **foreign data wrapper**
  - handler for — [Writing a Foreign Data Wrapper](fdwhandler.md)
- **foreign key** — [Foreign Keys](tutorial-fk.md), [Foreign Keys](ddl-constraints.md#ddl-constraints-fk)
  - self-referential — [Foreign Keys](ddl-constraints.md#ddl-constraints-fk)
- **foreign table** — [Foreign Data](ddl-foreign-data.md)
- **format** — [String Functions and Operators](functions-string.md), [`format`](functions-string.md#functions-string-format)
  - use in PL/pgSQL — [Executing Dynamic Commands](plpgsql-statements.md#plpgsql-statements-executing-dyn)
- **formatting** — [Data Type Formatting Functions](functions-formatting.md)
- **format_type** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **Free Space Map** — [Free Space Map](storage-fsm.md)
- **FreeBSD**
  - IPC configuration — [Shared Memory and Semaphores](kernel-resources.md#sysvipc)
  - shared library — [Compiling and Linking Dynamically-Loaded Functions](xfunc-c.md#dfunc)
  - start script — [Starting the Database Server](server-start.md)
- **from_collapse_limit configuration parameter** — [Other Planner Options](runtime-config-query.md#runtime-config-query-other)
- **FSM** — *see* Free Space Map
- **fsm_page_contents** — [General Functions](pageinspect.md#pageinspect-general-funcs)
- **fsync configuration parameter** — [Settings](runtime-config-wal.md#runtime-config-wal-settings)
- **full text search** — [Full Text Search](textsearch.md)
  - data types — [Text Search Types](datatype-textsearch.md)
  - functions and operators — [Text Search Functions and Operators](functions-textsearch.md)
- **full_page_writes configuration parameter** — [Settings](runtime-config-wal.md#runtime-config-wal-settings)
- **function** — [Functions and Operators](functions.md)
  - default values for arguments — [SQL Functions with Default Values for Arguments](xfunc-sql.md#xfunc-sql-parameter-defaults)
  - in the FROM clause — [Table Functions](queries-table-expressions.md#queries-tablefunctions)
  - internal — [Internal Functions](xfunc-internal.md)
  - invocation — [Function Calls](sql-expressions.md#sql-expressions-function-calls)
  - mixed notation — [Using Mixed Notation](sql-syntax-calling-funcs.md#sql-syntax-calling-funcs-mixed)
  - named argument — [Arguments for SQL Functions](xfunc-sql.md#xfunc-sql-function-arguments)
  - named notation — [Using Named Notation](sql-syntax-calling-funcs.md#sql-syntax-calling-funcs-named)
  - output parameter — [SQL Functions with Output Parameters](xfunc-sql.md#xfunc-output-parameters)
  - polymorphic — [Polymorphic Types](extend-type-system.md#extend-types-polymorphic)
  - positional notation — [Using Positional Notation](sql-syntax-calling-funcs.md#sql-syntax-calling-funcs-positional)
  - RETURNS TABLE — [SQL Functions Returning `TABLE`](xfunc-sql.md#xfunc-sql-functions-returning-table)
  - statistics — [Statistics Information Functions](functions-statistics.md)
  - type resolution in an invocation — [Functions](typeconv-func.md)
  - user-defined — [User-Defined Functions](xfunc.md)
    - in C — [C-Language Functions](xfunc-c.md)
    - in SQL — [Query Language (SQL) Functions](xfunc-sql.md)
  - variadic — [SQL Functions with Variable Numbers of Arguments](xfunc-sql.md#xfunc-sql-variadic-functions)
  - with SETOF — [SQL Functions Returning Sets](xfunc-sql.md#xfunc-sql-functions-returning-set)
- **functional dependency** — [The `GROUP BY` and `HAVING` Clauses](queries-table-expressions.md#queries-group)
- **fuzzystrmatch** — [fuzzystrmatch — determine string similarities and distance](fuzzystrmatch.md)

## G

- **gamma** — [Mathematical Functions and Operators](functions-math.md)
- **gcd** — [Mathematical Functions and Operators](functions-math.md)
- **gc_to_sec** — [Cube-Based Earth Distances](earthdistance.md#earthdistance-cube-based)
- **generated column** — [Generated Columns](ddl-generated-columns.md), [Parameters](sql-createforeigntable.md#sql-createforeigntable-parameters), [Parameters](sql-createtable.md#id-1.9.3.87.6)
  - in
    triggers — [Overview of Trigger Behavior](trigger-definition.md)
- **generate_series** — [Set Returning Functions](functions-srf.md)
- **generate_subscripts** — [Set Returning Functions](functions-srf.md)
- **genetic query optimization** — [Genetic Query Optimizer](runtime-config-query.md#runtime-config-query-geqo)
- **gen_random_bytes** — [Random-Data Functions](pgcrypto.md#pgcrypto-random-data-funcs)
- **gen_random_uuid** — [UUID Functions](functions-uuid.md), [Random-Data Functions](pgcrypto.md#pgcrypto-random-data-funcs)
- **gen_salt** — [`gen_salt()`](pgcrypto.md#pgcrypto-password-hashing-funcs-gen-salt)
- **GEQO** — *see* genetic query optimization
- **geqo configuration parameter** — [Genetic Query Optimizer](runtime-config-query.md#runtime-config-query-geqo)
- **geqo_effort configuration parameter** — [Genetic Query Optimizer](runtime-config-query.md#runtime-config-query-geqo)
- **geqo_generations configuration parameter** — [Genetic Query Optimizer](runtime-config-query.md#runtime-config-query-geqo)
- **geqo_pool_size configuration parameter** — [Genetic Query Optimizer](runtime-config-query.md#runtime-config-query-geqo)
- **geqo_seed configuration parameter** — [Genetic Query Optimizer](runtime-config-query.md#runtime-config-query-geqo)
- **geqo_selection_bias configuration parameter** — [Genetic Query Optimizer](runtime-config-query.md#runtime-config-query-geqo)
- **geqo_threshold configuration parameter** — [Genetic Query Optimizer](runtime-config-query.md#runtime-config-query-geqo)
- **get_bit** — [Binary String Functions and Operators](functions-binarystring.md), [Bit String Functions and Operators](functions-bitstring.md)
- **get_byte** — [Binary String Functions and Operators](functions-binarystring.md)
- **get_current_ts_config** — [Text Search Functions and Operators](functions-textsearch.md)
- **get_raw_page** — [General Functions](pageinspect.md#pageinspect-general-funcs)
- **GIN** — *see* index
- **gin_clean_pending_list** — [Index Maintenance Functions](functions-admin.md#functions-admin-index)
- **gin_fuzzy_search_limit configuration parameter** — [Other Defaults](runtime-config-client.md#runtime-config-client-other)
- **gin_index_check** — [Functions](amcheck.md#amcheck-functions)
- **gin_leafpage_items** — [GIN Functions](pageinspect.md#pageinspect-gin-funcs)
- **gin_metapage_info** — [GIN Functions](pageinspect.md#pageinspect-gin-funcs)
- **gin_page_opaque_info** — [GIN Functions](pageinspect.md#pageinspect-gin-funcs)
- **gin_pending_list_limit**
  - configuration parameter — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
  - storage parameter — [Index Storage Parameters](sql-createindex.md#sql-createindex-storage-parameters)
- **GiST** — *see* index
- **gist_page_items** — [GiST Functions](pageinspect.md#pageinspect-gist-funcs)
- **gist_page_items_bytea** — [GiST Functions](pageinspect.md#pageinspect-gist-funcs)
- **gist_page_opaque_info** — [GiST Functions](pageinspect.md#pageinspect-gist-funcs)
- **Git** — [The Source Code Repository](sourcerepo.md)
- **global data**
  - in PL/Python — [Sharing Data](plpython-sharing.md)
  - in PL/Tcl — [Global Data in PL/Tcl](pltcl-global.md)
- **GRANT** — [Privileges](ddl-priv.md), [GRANT](sql-grant.md)
- **GREATEST** — [`GREATEST` and `LEAST`](functions-conditional.md#functions-greatest-least)
  - determination of result type — [`UNION`, `CASE`, and Related Constructs](typeconv-union-case.md)
- **Gregorian calendar** — [History of Units](datetime-units-history.md)
- **GROUP BY** — [Aggregate Functions](tutorial-agg.md), [The `GROUP BY` and `HAVING` Clauses](queries-table-expressions.md#queries-group)
- **grouping** — [The `GROUP BY` and `HAVING` Clauses](queries-table-expressions.md#queries-group)
- **GROUPING** — [Aggregate Functions](functions-aggregate.md)
- **GROUPING SETS** — [`GROUPING SETS`, `CUBE`, and `ROLLUP`](queries-table-expressions.md#queries-grouping-sets)
- **gssapi** — [Secure TCP/IP Connections with GSSAPI Encryption](gssapi-enc.md)
- **GSSAPI** — [GSSAPI Authentication](gssapi-auth.md)
  - with
        libpq — [Parameter Key Words](libpq-connect.md#libpq-paramkeywords)
- **gss_accept_delegation configuration parameter** — [Authentication](runtime-config-connection.md#runtime-config-connection-authentication)
- **GUC** — [Setting Parameters](config-setting.md)
- **GUID** — [UUID Type](datatype-uuid.md)

## H

- **hash** — *see* index
- **hash_bitmap_info** — [Hash Functions](pageinspect.md#pageinspect-hash-funcs)
- **hash_mem_multiplier configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **hash_metapage_info** — [Hash Functions](pageinspect.md#pageinspect-hash-funcs)
- **hash_page_items** — [Hash Functions](pageinspect.md#pageinspect-hash-funcs)
- **hash_page_stats** — [Hash Functions](pageinspect.md#pageinspect-hash-funcs)
- **hash_page_type** — [Hash Functions](pageinspect.md#pageinspect-hash-funcs)
- **has_any_column_privilege** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **has_column_privilege** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **has_database_privilege** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **has_foreign_data_wrapper_privilege** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **has_function_privilege** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **has_language_privilege** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **has_largeobject_privilege** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **has_parameter_privilege** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **has_schema_privilege** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **has_sequence_privilege** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **has_server_privilege** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **has_tablespace_privilege** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **has_table_privilege** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **has_type_privilege** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **HAVING** — [Aggregate Functions](tutorial-agg.md), [The `GROUP BY` and `HAVING` Clauses](queries-table-expressions.md#queries-group)
- **hba_file configuration parameter** — [File Locations](runtime-config-file-locations.md)
- **heap_page_items** — [Heap Functions](pageinspect.md#pageinspect-heap-funcs)
- **heap_page_item_attrs** — [Heap Functions](pageinspect.md#pageinspect-heap-funcs)
- **heap_tuple_infomask_flags** — [Heap Functions](pageinspect.md#pageinspect-heap-funcs)
- **height** — [Geometric Functions and Operators](functions-geometry.md)
- **hex format** — [Binary String Functions and Operators](functions-binarystring.md)
- **hierarchical database** — [Concepts](tutorial-concepts.md)
- **high availability** — [High Availability, Load Balancing, and Replication](high-availability.md)
- **history**
  - of PostgreSQL — [A Brief History of PostgreSQL](history.md)
- **hmac** — [`hmac()`](pgcrypto.md#pgcrypto-general-hashing-funcs-hmac)
- **host** — [Network Address Functions and Operators](functions-net.md)
- **host
        name** — [Parameter Key Words](libpq-connect.md#libpq-paramkeywords)
- **hostmask** — [Network Address Functions and Operators](functions-net.md)
- **hosts_file configuration parameter** — [File Locations](runtime-config-file-locations.md)
- **hot standby** — [Hot Standby](hot-standby.md)
- **hot_standby configuration parameter** — [Standby Servers](runtime-config-replication.md#runtime-config-replication-standby)
- **hot_standby_feedback configuration parameter** — [Standby Servers](runtime-config-replication.md#runtime-config-replication-standby)
- **hstore** — [hstore — hstore key/value datatype](hstore.md), [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **hstore_to_array** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **hstore_to_json** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **hstore_to_jsonb** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **hstore_to_jsonb_loose** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **hstore_to_json_loose** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **hstore_to_matrix** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **huge_pages configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **huge_pages_status configuration parameter** — [Preset Options](runtime-config-preset.md)
- **huge_page_size configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **hypothetical-set aggregate**
  - built-in — [Aggregate Functions](functions-aggregate.md)

## I

- **icount** — [`intarray` Functions and Operators](intarray.md#intarray-funcs-ops)
- **ICU** — [Anti-Features](install-make.md#configure-options-anti-features), [PostgreSQL Features](install-meson.md#meson-options-features), [Locale Providers](locale.md#locale-providers), [Managing Collations](collation.md#collation-managing), [Parameters](sql-createcollation.md#id-1.9.3.60.6), [Parameters](sql-createdatabase.md#id-1.9.3.62.6)
- **icu_unicode_version** — [Version Information Functions](functions-info.md#functions-info-version)
- **icu_validation_level configuration parameter** — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)
- **ident** — [Ident Authentication](auth-ident.md)
- **identifier**
  - length — [Identifiers and Key Words](sql-syntax-lexical.md#sql-syntax-identifiers)
  - syntax of — [Identifiers and Key Words](sql-syntax-lexical.md#sql-syntax-identifiers)
- **IDENTIFY_SYSTEM** — [Streaming Replication Protocol](protocol-replication.md)
- **identity column** — [Identity Columns](ddl-identity-columns.md)
- **ident_file configuration parameter** — [File Locations](runtime-config-file-locations.md)
- **idle_in_transaction_session_timeout configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **idle_replication_slot_timeout configuration parameter** — [Sending Servers](runtime-config-replication.md#runtime-config-replication-sender)
- **idle_session_timeout configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **idx** — [`intarray` Functions and Operators](intarray.md#intarray-funcs-ops)
- **IFNULL** — [`COALESCE`](functions-conditional.md#functions-coalesce-nvl-ifnull)
- **ignore_checksum_failure configuration parameter** — [Developer Options](runtime-config-developer.md)
- **ignore_invalid_pages configuration parameter** — [Developer Options](runtime-config-developer.md)
- **ignore_system_indexes configuration parameter** — [Developer Options](runtime-config-developer.md)
- **IMMUTABLE** — [Function Volatility Categories](xfunc-volatility.md)
- **IMPORT FOREIGN SCHEMA** — [IMPORT FOREIGN SCHEMA](sql-importforeignschema.md)
- **IN** — [Subquery Expressions](functions-subquery.md), [Row and Array Comparisons](functions-comparisons.md)
- **INCLUDE**
  - in index definitions — [Index-Only Scans and Covering Indexes](indexes-index-only-scans.md)
- **include**
  - in configuration file — [Managing Configuration File Contents](config-setting.md#config-includes)
- **include_dir**
  - in configuration file — [Managing Configuration File Contents](config-setting.md#config-includes)
- **include_if_exists**
  - in configuration file — [Managing Configuration File Contents](config-setting.md#config-includes)
- **index** — [Indexes](indexes.md), [Operators and Functions](ltree.md#ltree-ops-funcs)
  - and ORDER BY — [Indexes and `ORDER BY`](indexes-ordering.md)
  - B-Tree — [B-Tree](indexes-types.md#indexes-types-btree), [B-Tree Indexes](btree.md)
  - BRIN — [BRIN](indexes-types.md#indexes-types-brin), [BRIN Indexes](brin.md)
  - building concurrently — [Building Indexes Concurrently](sql-createindex.md#sql-createindex-concurrently)
  - combining multiple indexes — [Combining Multiple Indexes](indexes-bitmap-scans.md)
  - covering — [Index-Only Scans and Covering Indexes](indexes-index-only-scans.md)
  - examining usage — [Examining Index Usage](indexes-examine.md)
  - on expressions — [Indexes on Expressions](indexes-expressional.md)
  - for user-defined data type — [Interfacing Extensions to Indexes](xindex.md)
  - GIN — [GIN](indexes-types.md#indexes-types-gin), [GIN Indexes](gin.md)
    - text search — [Preferred Index Types for Text Search](textsearch-indexes.md)
  - GiST — [GiST](indexes-types.md#indexes-type-gist), [GiST Indexes](gist.md)
    - text search — [Preferred Index Types for Text Search](textsearch-indexes.md)
  - hash — [Hash](indexes-types.md#indexes-types-hash)
  - Hash — [Hash Indexes](hash-index.md)
  - index-only scans — [Index-Only Scans and Covering Indexes](indexes-index-only-scans.md)
  - locks — [Locking and Indexes](locking-indexes.md)
  - multicolumn — [Multicolumn Indexes](indexes-multicolumn.md)
  - partial — [Partial Indexes](indexes-partial.md)
  - rebuilding concurrently — [Rebuilding Indexes Concurrently](sql-reindex.md#sql-reindex-concurrently)
  - SP-GiST — [SP-GiST](indexes-types.md#indexes-type-spgist), [SP-GiST Indexes](spgist.md)
  - unique — [Unique Indexes](indexes-unique.md)
- **Index Access Method** — [Index Access Method Interface Definition](indexam.md)
- **index scan** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **index-only scan** — [Index-Only Scans and Covering Indexes](indexes-index-only-scans.md)
- **indexam**
  - Index Access Method — [Index Access Method Interface Definition](indexam.md)
- **index_am_handler** — [Pseudo-Types](datatype-pseudo.md)
- **inet (data type)** — [`inet`](datatype-net-types.md#datatype-inet)
- **inet_client_addr** — [Session Information Functions](functions-info.md#functions-info-session)
- **inet_client_port** — [Session Information Functions](functions-info.md#functions-info-session)
- **inet_merge** — [Network Address Functions and Operators](functions-net.md)
- **inet_same_family** — [Network Address Functions and Operators](functions-net.md)
- **inet_server_addr** — [Session Information Functions](functions-info.md#functions-info-session)
- **inet_server_port** — [Session Information Functions](functions-info.md#functions-info-session)
- **infinity**
  - floating point — [Floating-Point Types](datatype-numeric.md#datatype-float)
  - numeric (data type) — [Arbitrary Precision Numbers](datatype-numeric.md#datatype-numeric-decimal)
- **information schema** — [The Information Schema](information-schema.md)
- **inheritance** — [Inheritance](tutorial-inheritance.md), [Inheritance](ddl-inherit.md)
- **initcap** — [String Functions and Operators](functions-string.md)
- **initdb** — [Creating a Database Cluster](creating-cluster.md), [initdb](app-initdb.md)
- **Initialization Fork** — [The Initialization Fork](storage-init.md)
- **initplan** — [`EXPLAIN` Basics](using-explain.md#using-explain-basics)
- **input function** — [User-Defined Types](xtypes.md)
- **INSERT** — [Populating a Table With Rows](tutorial-populate.md), [Inserting Data](dml-insert.md), [INSERT](sql-insert.md)
  - RETURNING — [Returning Data from Modified Rows](dml-returning.md)
- **inserting** — [Inserting Data](dml-insert.md)
- **installation** — [Installation from Source Code](installation.md)
  - binaries — [Installation from Binaries](install-binaries.md)
- **instr function** — [Appendix](plpgsql-porting.md#plpgsql-porting-appendix)
- **int2** — *see* smallint
- **int4** — *see* integer
- **int8** — *see* bigint
- **intagg** — [intagg — integer aggregator and enumerator](intagg.md)
- **intarray** — [intarray — manipulate arrays of integers](intarray.md)
- **integer** — [Numeric Constants](sql-syntax-lexical.md#sql-syntax-constants-numeric), [Integer Types](datatype-numeric.md#datatype-int)
- **integer_datetimes configuration parameter** — [Preset Options](runtime-config-preset.md)
- **interfaces**
  - externally maintained — [Client Interfaces](external-interfaces.md)
- **internal** — [Pseudo-Types](datatype-pseudo.md)
- **INTERSECT** — [Combining Queries (`UNION`, `INTERSECT`, `EXCEPT`)](queries-union.md)
- **interval** — [Date/Time Types](datatype-datetime.md), [Interval Input](datatype-datetime.md#datatype-interval-input)
  - output format — [Interval Output](datatype-datetime.md#datatype-interval-output); *see also* formatting
- **IntervalStyle configuration parameter** — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)
- **intset** — [`intarray` Functions and Operators](intarray.md#intarray-funcs-ops)
- **int_array_aggregate** — [Functions](intagg.md#intagg-functions)
- **int_array_enum** — [Functions](intagg.md#intagg-functions)
- **inverse distribution** — [Aggregate Functions](functions-aggregate.md)
- **in_hot_standby configuration parameter** — [Preset Options](runtime-config-preset.md)
- **in_range support functions** — [B-Tree Support Functions](btree.md#btree-support-funcs)
- **io_combine_limit configuration parameter** — [I/O](runtime-config-resource.md#runtime-config-resource-io)
- **io_max_combine_limit configuration parameter** — [I/O](runtime-config-resource.md#runtime-config-resource-io)
- **io_max_concurrency configuration parameter** — [I/O](runtime-config-resource.md#runtime-config-resource-io)
- **io_max_workers configuration parameter** — [I/O](runtime-config-resource.md#runtime-config-resource-io)
- **io_method configuration parameter** — [I/O](runtime-config-resource.md#runtime-config-resource-io)
- **io_min_workers configuration parameter** — [I/O](runtime-config-resource.md#runtime-config-resource-io)
- **io_worker_idle_timeout configuration parameter** — [I/O](runtime-config-resource.md#runtime-config-resource-io)
- **io_worker_launch_interval configuration parameter** — [I/O](runtime-config-resource.md#runtime-config-resource-io)
- **IS DISTINCT FROM** — [Comparison Functions and Operators](functions-comparison.md), [Row and Array Comparisons](functions-comparisons.md)
- **IS DOCUMENT** — [`IS DOCUMENT`](functions-xml.md#functions-producing-xml-is-document)
- **IS FALSE** — [Comparison Functions and Operators](functions-comparison.md)
- **IS JSON** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **IS NOT DISTINCT FROM** — [Comparison Functions and Operators](functions-comparison.md), [Row and Array Comparisons](functions-comparisons.md)
- **IS NOT DOCUMENT** — [`IS NOT DOCUMENT`](functions-xml.md#functions-producing-xml-is-not-document)
- **IS NOT FALSE** — [Comparison Functions and Operators](functions-comparison.md)
- **IS NOT NULL** — [Comparison Functions and Operators](functions-comparison.md)
- **IS NOT TRUE** — [Comparison Functions and Operators](functions-comparison.md)
- **IS NOT UNKNOWN** — [Comparison Functions and Operators](functions-comparison.md)
- **IS NULL** — [Comparison Functions and Operators](functions-comparison.md), [Platform and Client Compatibility](runtime-config-compatible.md#runtime-config-compatible-clients)
- **IS TRUE** — [Comparison Functions and Operators](functions-comparison.md)
- **IS UNKNOWN** — [Comparison Functions and Operators](functions-comparison.md)
- **isclosed** — [Geometric Functions and Operators](functions-geometry.md)
- **isempty** — [Range/Multirange Functions and Operators](functions-range.md), [Range/Multirange Functions and Operators](functions-range.md)
- **isfinite** — [Date/Time Functions and Operators](functions-datetime.md)
- **isn** — [isn — data types for international standard numbers (ISBN, EAN, UPC, etc.)](isn.md)
- **isn.weak configuration parameter** — [Configuration Parameters](isn.md#isn-configuration-parameters)
- **ISNULL** — [Comparison Functions and Operators](functions-comparison.md)
- **isn_weak** — [Functions and Operators](isn.md#isn-funcs-ops)
- **isopen** — [Geometric Functions and Operators](functions-geometry.md)
- **is_array_ref**
  - in PL/Perl — [Utility Functions in PL/Perl](plperl-builtins.md#plperl-utility-functions)
- **is_valid** — [Functions and Operators](isn.md#isn-funcs-ops)

## J

- **JIT** — [Just-in-Time Compilation (JIT)](jit.md)
- **jit configuration parameter** — [Other Planner Options](runtime-config-query.md#runtime-config-query-other)
- **jit_above_cost configuration parameter** — [Planner Cost Constants](runtime-config-query.md#runtime-config-query-constants)
- **jit_debugging_support configuration parameter** — [Developer Options](runtime-config-developer.md)
- **jit_dump_bitcode configuration parameter** — [Developer Options](runtime-config-developer.md)
- **jit_expressions configuration parameter** — [Developer Options](runtime-config-developer.md)
- **jit_inline_above_cost configuration parameter** — [Planner Cost Constants](runtime-config-query.md#runtime-config-query-constants)
- **jit_optimize_above_cost configuration parameter** — [Planner Cost Constants](runtime-config-query.md#runtime-config-query-constants)
- **jit_profiling_support configuration parameter** — [Developer Options](runtime-config-developer.md)
- **jit_provider configuration parameter** — [Shared Library Preloading](runtime-config-client.md#runtime-config-client-preload)
- **jit_tuple_deforming configuration parameter** — [Developer Options](runtime-config-developer.md)
- **join** — [Joins Between Tables](tutorial-join.md), [Joined Tables](queries-table-expressions.md#queries-join)
  - controlling the order — [Controlling the Planner with Explicit `JOIN` Clauses](explicit-joins.md)
  - cross — [Joined Tables](queries-table-expressions.md#queries-join)
  - left — [Joined Tables](queries-table-expressions.md#queries-join)
  - natural — [Joined Tables](queries-table-expressions.md#queries-join)
  - outer — [Joins Between Tables](tutorial-join.md), [Joined Tables](queries-table-expressions.md#queries-join)
  - right — [Joined Tables](queries-table-expressions.md#queries-join)
  - self — [Joins Between Tables](tutorial-join.md)
- **join_collapse_limit configuration parameter** — [Other Planner Options](runtime-config-query.md#runtime-config-query-other)
- **JSON** — [JSON Types](datatype-json.md)
  - functions and operators — [JSON Functions and Operators](functions-json.md)
- **json constructor** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **JSONB** — [JSON Types](datatype-json.md)
- **jsonb**
  - containment — [`jsonb` Containment and Existence](datatype-json.md#json-containment)
  - existence — [`jsonb` Containment and Existence](datatype-json.md#json-containment)
  - indexes on — [`jsonb` Indexing](datatype-json.md#json-indexing)
- **jsonb_agg** — [Aggregate Functions](functions-aggregate.md)
- **jsonb_agg_strict** — [Aggregate Functions](functions-aggregate.md)
- **jsonb_array_elements** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_array_elements_text** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_array_length** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_build_array** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_build_object** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_each** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_each_text** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_extract_path** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_extract_path_text** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_insert** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_object** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_object_agg** — [Aggregate Functions](functions-aggregate.md)
- **jsonb_object_agg_strict** — [Aggregate Functions](functions-aggregate.md)
- **jsonb_object_agg_unique** — [Aggregate Functions](functions-aggregate.md)
- **jsonb_object_agg_unique_strict** — [Aggregate Functions](functions-aggregate.md)
- **jsonb_object_keys** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_path_exists** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_path_exists_tz** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_path_match** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_path_match_tz** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_path_query** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_path_query_array** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_path_query_array_tz** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_path_query_first** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_path_query_first_tz** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_path_query_tz** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_populate_record** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_populate_recordset** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_populate_record_valid** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_pretty** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_set** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_set_lax** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_strip_nulls** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_to_record** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_to_recordset** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonb_to_tsvector** — [Text Search Functions and Operators](functions-textsearch.md)
- **jsonb_typeof** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **jsonpath** — [jsonpath Type](datatype-json.md#datatype-jsonpath)
- **json_agg** — [Aggregate Functions](functions-aggregate.md)
- **json_agg_strict** — [Aggregate Functions](functions-aggregate.md)
- **json_array** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_arrayagg** — [Aggregate Functions](functions-aggregate.md)
- **json_array_elements** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_array_elements_text** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_array_length** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_build_array** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_build_object** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_each** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_each_text** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_exists** — [SQL/JSON Query Functions](functions-json.md#sqljson-query-functions)
- **json_extract_path** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_extract_path_text** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_object** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing), [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_objectagg** — [Aggregate Functions](functions-aggregate.md)
- **json_object_agg** — [Aggregate Functions](functions-aggregate.md)
- **json_object_agg_strict** — [Aggregate Functions](functions-aggregate.md)
- **json_object_agg_unique** — [Aggregate Functions](functions-aggregate.md)
- **json_object_agg_unique_strict** — [Aggregate Functions](functions-aggregate.md)
- **json_object_keys** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_populate_record** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_populate_recordset** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_query** — [SQL/JSON Query Functions](functions-json.md#sqljson-query-functions)
- **json_scalar** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_strip_nulls** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_table** — [JSON_TABLE](functions-json.md#functions-sqljson-table)
- **json_to_record** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_to_recordset** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_to_tsvector** — [Text Search Functions and Operators](functions-textsearch.md)
- **json_typeof** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **json_value** — [SQL/JSON Query Functions](functions-json.md#sqljson-query-functions)
- **Julian date** — [Julian Dates](datetime-julian-dates.md)
- **Just-In-Time compilation** — *see* JIT
- **justify_days** — [Date/Time Functions and Operators](functions-datetime.md)
- **justify_hours** — [Date/Time Functions and Operators](functions-datetime.md)
- **justify_interval** — [Date/Time Functions and Operators](functions-datetime.md)

## K

- **key word**
  - list of — [SQL Key Words](sql-keywords-appendix.md)
  - syntax of — [Identifiers and Key Words](sql-syntax-lexical.md#sql-syntax-identifiers)
- **krb_caseins_users configuration parameter** — [Authentication](runtime-config-connection.md#runtime-config-connection-authentication)
- **krb_server_keyfile configuration parameter** — [Authentication](runtime-config-connection.md#runtime-config-connection-authentication)

## L

- **label** — *see* alias
- **lag** — [Window Functions](functions-window.md)
- **language_handler** — [Pseudo-Types](datatype-pseudo.md)
- **large object** — [Large Objects](largeobjects.md)
- **lastval** — [Sequence Manipulation Functions](functions-sequence.md)
- **last_value** — [Window Functions](functions-window.md)
- **LATERAL**
  - in the FROM clause — [`LATERAL` Subqueries](queries-table-expressions.md#queries-lateral)
- **latitude** — [Cube-Based Earth Distances](earthdistance.md#earthdistance-cube-based)
- **lca** — [Operators and Functions](ltree.md#ltree-ops-funcs)
- **lcm** — [Mathematical Functions and Operators](functions-math.md)
- **lc_messages configuration parameter** — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)
- **lc_monetary configuration parameter** — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)
- **lc_numeric configuration parameter** — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)
- **lc_time configuration parameter** — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)
- **LDAP** — [PostgreSQL Features](install-make.md#configure-options-features), [PostgreSQL Features](install-meson.md#meson-options-features), [LDAP Authentication](auth-ldap.md)
- **LDAP connection parameter lookup** — [LDAP Lookup of Connection Parameters](libpq-ldap.md)
- **ldconfig** — [Shared Libraries](install-post.md#install-post-shlibs)
- **lead** — [Window Functions](functions-window.md)
- **LEAST** — [`GREATEST` and `LEAST`](functions-conditional.md#functions-greatest-least)
  - determination of result type — [`UNION`, `CASE`, and Related Constructs](typeconv-union-case.md)
- **left** — [String Functions and Operators](functions-string.md)
- **left join** — [Joined Tables](queries-table-expressions.md#queries-join)
- **length** — [String Functions and Operators](functions-string.md), [Binary String Functions and Operators](functions-binarystring.md), [Bit String Functions and Operators](functions-bitstring.md), [Geometric Functions and Operators](functions-geometry.md), [Text Search Functions and Operators](functions-textsearch.md)
  - of a binary string — *see* binary strings, length
  - of a character string — *see* character string, length
- **length(tsvector)** — [Manipulating Documents](textsearch-features.md#textsearch-manipulate-tsvector)
- **levenshtein** — [Levenshtein](fuzzystrmatch.md#fuzzystrmatch-levenshtein)
- **levenshtein_less_equal** — [Levenshtein](fuzzystrmatch.md#fuzzystrmatch-levenshtein)
- **lex** — [Requirements](install-requirements.md)
- **lgamma** — [Mathematical Functions and Operators](functions-math.md)
- **libedit** — [Requirements](install-requirements.md)
  - in psql — [Command-Line Editing](app-psql.md#app-psql-readline)
- **libperl** — [Requirements](install-requirements.md)
- **libpq** — [libpq — C Library](libpq.md)
  - chunked mode — [Retrieving Query Results in Chunks](libpq-single-row-mode.md)
  - pipeline mode — [Pipeline Mode](libpq-pipeline-mode.md)
  - single-row mode — [Retrieving Query Results in Chunks](libpq-single-row-mode.md)
- **libpq-fe.h** — [libpq — C Library](libpq.md), [Connection Status Functions](libpq-status.md)
- **libpq-int.h** — [Connection Status Functions](libpq-status.md)
- **libpython** — [Requirements](install-requirements.md)
- **library initialization function** — [Dynamic Loading](xfunc-c.md#xfunc-c-dynload)
- **LIKE** — [`LIKE`](functions-matching.md#functions-like)
  - and locales — [Behavior](locale.md#locale-behavior)
- **LIKE_REGEX** — [Differences from SQL Standard and XQuery](functions-matching.md#posix-vs-xquery)
  - in SQL/JSON — [SQL/JSON Regular Expressions](functions-json.md#jsonpath-regular-expressions)
- **LIMIT** — [`LIMIT` and `OFFSET`](queries-limit.md)
- **line** — [Lines](datatype-geometric.md#datatype-line), [Geometric Functions and Operators](functions-geometry.md)
- **line segment** — [Line Segments](datatype-geometric.md#datatype-lseg)
- **linear regression** — [Aggregate Functions](functions-aggregate.md)
- **Linux**
  - IPC configuration — [Shared Memory and Semaphores](kernel-resources.md#sysvipc)
  - shared library — [Compiling and Linking Dynamically-Loaded Functions](xfunc-c.md#dfunc)
  - start script — [Starting the Database Server](server-start.md)
- **LISTEN** — [LISTEN](sql-listen.md)
- **listen_addresses configuration parameter** — [Connection Settings](runtime-config-connection.md#runtime-config-connection-settings)
- **llvm-config** — [PostgreSQL Features](install-make.md#configure-options-features), [PostgreSQL Features](install-meson.md#meson-options-features)
- **ll_to_earth** — [Cube-Based Earth Distances](earthdistance.md#earthdistance-cube-based)
- **ln** — [Mathematical Functions and Operators](functions-math.md)
- **lo** — [lo — manage large objects](lo.md)
- **LOAD** — [LOAD](sql-load.md)
- **load balancing** — [High Availability, Load Balancing, and Replication](high-availability.md)
- **locale** — [Creating a Database Cluster](creating-cluster.md), [Locale Support](locale.md)
- **localtime** — [Date/Time Functions and Operators](functions-datetime.md)
- **localtimestamp** — [Date/Time Functions and Operators](functions-datetime.md)
- **local_preload_libraries configuration parameter** — [Shared Library Preloading](runtime-config-client.md#runtime-config-client-preload)
- **lock** — [Explicit Locking](explicit-locking.md)
  - advisory — [Advisory Locks](explicit-locking.md#advisory-locks)
  - monitoring — [Viewing Locks](monitoring-locks.md)
- **LOCK** — [Table-Level Locks](explicit-locking.md#locking-tables), [LOCK](sql-lock.md)
- **lock_timeout configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **log** — [Mathematical Functions and Operators](functions-math.md)
- **log shipping** — [Log-Shipping Standby Servers](warm-standby.md)
- **log10** — [Mathematical Functions and Operators](functions-math.md)
- **Logging**
  - current_logfiles file and the pg_current_logfile
         function — [Session Information Functions](functions-info.md#functions-info-session)
  - pg_current_logfile function — [Session Information Functions](functions-info.md#functions-info-session)
- **logging_collector configuration parameter** — [Where to Log](runtime-config-logging.md#runtime-config-logging-where)
- **Logical Decoding** — [Logical Decoding](logicaldecoding.md), [Logical Decoding](logicaldecoding-explanation.md#logicaldecoding-explanation-log-dec)
- **logical_decoding_work_mem configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **login privilege** — [Role Attributes](role-attributes.md)
- **log_autoanalyze_min_duration**
  - configuration parameter — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
  - storage parameter — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **log_autovacuum_min_duration**
  - configuration parameter — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
  - storage parameter — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **log_btree_build_stats configuration parameter** — [Developer Options](runtime-config-developer.md)
- **log_checkpoints configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_connections configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_destination configuration parameter** — [Where to Log](runtime-config-logging.md#runtime-config-logging-where)
- **log_directory configuration parameter** — [Where to Log](runtime-config-logging.md#runtime-config-logging-where)
- **log_disconnections configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_duration configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_error_verbosity configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_executor_stats configuration parameter** — [Statistics Monitoring](runtime-config-statistics.md#runtime-config-statistics-monitor)
- **log_filename configuration parameter** — [Where to Log](runtime-config-logging.md#runtime-config-logging-where)
- **log_file_mode configuration parameter** — [Where to Log](runtime-config-logging.md#runtime-config-logging-where)
- **log_hostname configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_line_prefix configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_lock_failures configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_lock_waits configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_min_duration_sample configuration parameter** — [When to Log](runtime-config-logging.md#runtime-config-logging-when)
- **log_min_duration_statement configuration parameter** — [When to Log](runtime-config-logging.md#runtime-config-logging-when)
- **log_min_error_statement configuration parameter** — [When to Log](runtime-config-logging.md#runtime-config-logging-when)
- **log_min_messages configuration parameter** — [When to Log](runtime-config-logging.md#runtime-config-logging-when)
- **log_parameter_max_length configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_parameter_max_length_on_error configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_parser_stats configuration parameter** — [Statistics Monitoring](runtime-config-statistics.md#runtime-config-statistics-monitor)
- **log_planner_stats configuration parameter** — [Statistics Monitoring](runtime-config-statistics.md#runtime-config-statistics-monitor)
- **log_recovery_conflict_waits configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_replication_commands configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_rotation_age configuration parameter** — [Where to Log](runtime-config-logging.md#runtime-config-logging-where)
- **log_rotation_size configuration parameter** — [Where to Log](runtime-config-logging.md#runtime-config-logging-where)
- **log_startup_progress_interval configuration parameter** — [When to Log](runtime-config-logging.md#runtime-config-logging-when)
- **log_statement configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_statement_max_length configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_statement_sample_rate configuration parameter** — [When to Log](runtime-config-logging.md#runtime-config-logging-when)
- **log_statement_stats configuration parameter** — [Statistics Monitoring](runtime-config-statistics.md#runtime-config-statistics-monitor)
- **log_temp_files configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_timezone configuration parameter** — [What to Log](runtime-config-logging.md#runtime-config-logging-what)
- **log_transaction_sample_rate configuration parameter** — [When to Log](runtime-config-logging.md#runtime-config-logging-when)
- **log_truncate_on_rotation configuration parameter** — [Where to Log](runtime-config-logging.md#runtime-config-logging-where)
- **longitude** — [Cube-Based Earth Distances](earthdistance.md#earthdistance-cube-based)
- **looks_like_number**
  - in PL/Perl — [Utility Functions in PL/Perl](plperl-builtins.md#plperl-utility-functions)
- **loop**
  - in PL/pgSQL — [Simple Loops](plpgsql-control-structures.md#plpgsql-control-structures-loops)
- **lower** — [String Functions and Operators](functions-string.md), [Range/Multirange Functions and Operators](functions-range.md), [Range/Multirange Functions and Operators](functions-range.md)
  - and locales — [Behavior](locale.md#locale-behavior)
- **lower_inc** — [Range/Multirange Functions and Operators](functions-range.md), [Range/Multirange Functions and Operators](functions-range.md)
- **lower_inf** — [Range/Multirange Functions and Operators](functions-range.md), [Range/Multirange Functions and Operators](functions-range.md)
- **lo_close** — [Closing a Large Object Descriptor](lo-interfaces.md#lo-close)
- **lo_compat_privileges configuration parameter** — [Previous PostgreSQL Versions](runtime-config-compatible.md#runtime-config-compatible-version)
- **lo_creat** — [Creating a Large Object](lo-interfaces.md#lo-create), [Server-Side Functions](lo-funcs.md)
- **lo_create** — [Creating a Large Object](lo-interfaces.md#lo-create)
- **lo_export** — [Exporting a Large Object](lo-interfaces.md#lo-export), [Server-Side Functions](lo-funcs.md)
- **lo_from_bytea** — [Server-Side Functions](lo-funcs.md)
- **lo_get** — [Server-Side Functions](lo-funcs.md)
- **lo_import** — [Importing a Large Object](lo-interfaces.md#lo-import), [Server-Side Functions](lo-funcs.md)
- **lo_import_with_oid** — [Importing a Large Object](lo-interfaces.md#lo-import)
- **lo_lseek** — [Seeking in a Large Object](lo-interfaces.md#lo-seek)
- **lo_lseek64** — [Seeking in a Large Object](lo-interfaces.md#lo-seek)
- **lo_open** — [Opening an Existing Large Object](lo-interfaces.md#lo-open)
- **lo_put** — [Server-Side Functions](lo-funcs.md)
- **lo_read** — [Reading Data from a Large Object](lo-interfaces.md#lo-read)
- **lo_tell** — [Obtaining the Seek Position of a Large Object](lo-interfaces.md#lo-tell)
- **lo_tell64** — [Obtaining the Seek Position of a Large Object](lo-interfaces.md#lo-tell)
- **lo_truncate** — [Truncating a Large Object](lo-interfaces.md#lo-truncate)
- **lo_truncate64** — [Truncating a Large Object](lo-interfaces.md#lo-truncate)
- **lo_unlink** — [Removing a Large Object](lo-interfaces.md#lo-unlink), [Server-Side Functions](lo-funcs.md)
- **lo_write** — [Writing Data to a Large Object](lo-interfaces.md#lo-write)
- **lpad** — [String Functions and Operators](functions-string.md)
- **lseg** — [Line Segments](datatype-geometric.md#datatype-lseg), [Geometric Functions and Operators](functions-geometry.md)
- **LSN** — [WAL Internals](wal-internals.md)
- **ltree** — [ltree — hierarchical tree-like data type](ltree.md)
- **ltree2text** — [Operators and Functions](ltree.md#ltree-ops-funcs)
- **ltrim** — [String Functions and Operators](functions-string.md), [Binary String Functions and Operators](functions-binarystring.md)

## M

- **MAC address** — *see* macaddr
- **MAC address (EUI-64 format)** — *see* macaddr
- **macaddr (data type)** — [`macaddr`](datatype-net-types.md#datatype-macaddr)
- **macaddr8 (data type)** — [`macaddr8`](datatype-net-types.md#datatype-macaddr8)
- **macaddr8_set7bit** — [Network Address Functions and Operators](functions-net.md)
- **macOS**
  - installation on — [macOS](installation-platform-notes.md#installation-notes-macos)
  - IPC configuration — [Shared Memory and Semaphores](kernel-resources.md#sysvipc)
  - shared library — [Compiling and Linking Dynamically-Loaded Functions](xfunc-c.md#dfunc)
- **magic block** — [Dynamic Loading](xfunc-c.md#xfunc-c-dynload)
- **maintenance** — [Routine Database Maintenance Tasks](maintenance.md)
- **maintenance_io_concurrency configuration parameter** — [I/O](runtime-config-resource.md#runtime-config-resource-io)
- **maintenance_work_mem configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **make** — [Requirements](install-requirements.md)
- **makeaclitem** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **make_date** — [Date/Time Functions and Operators](functions-datetime.md)
- **make_interval** — [Date/Time Functions and Operators](functions-datetime.md)
- **make_time** — [Date/Time Functions and Operators](functions-datetime.md)
- **make_timestamp** — [Date/Time Functions and Operators](functions-datetime.md)
- **make_timestamptz** — [Date/Time Functions and Operators](functions-datetime.md)
- **make_valid** — [Functions and Operators](isn.md#isn-funcs-ops)
- **MANPATH** — [Environment Variables](install-post.md#install-post-env-vars)
- **masklen** — [Network Address Functions and Operators](functions-net.md)
- **materialized view**
  - implementation through rules — [Materialized Views](rules-materializedviews.md)
- **materialized views** — [pg_matviews](view-pg-matviews.md)
- **max** — [Aggregate Functions](functions-aggregate.md)
- **max_active_replication_origins configuration parameter** — [Subscribers](runtime-config-replication.md#runtime-config-replication-subscriber)
- **max_connections configuration parameter** — [Connection Settings](runtime-config-connection.md#runtime-config-connection-settings)
- **max_files_per_process configuration parameter** — [Kernel Resource Usage](runtime-config-resource.md#runtime-config-resource-kernel)
- **max_function_args configuration parameter** — [Preset Options](runtime-config-preset.md)
- **max_identifier_length configuration parameter** — [Preset Options](runtime-config-preset.md)
- **max_index_keys configuration parameter** — [Preset Options](runtime-config-preset.md)
- **max_locks_per_transaction configuration parameter** — [Lock Management](runtime-config-locks.md)
- **max_logical_replication_workers configuration parameter** — [Subscribers](runtime-config-replication.md#runtime-config-replication-subscriber)
- **max_notify_queue_pages configuration parameter** — [Disk](runtime-config-resource.md#runtime-config-resource-disk)
- **max_parallel_apply_workers_per_subscription configuration parameter** — [Subscribers](runtime-config-replication.md#runtime-config-replication-subscriber)
- **max_parallel_maintenance_workers configuration parameter** — [Worker Processes](runtime-config-resource.md#runtime-config-resource-worker-processes)
- **max_parallel_workers configuration parameter** — [Worker Processes](runtime-config-resource.md#runtime-config-resource-worker-processes)
- **max_parallel_workers_per_gather configuration parameter** — [Worker Processes](runtime-config-resource.md#runtime-config-resource-worker-processes)
- **max_pred_locks_per_page configuration parameter** — [Lock Management](runtime-config-locks.md)
- **max_pred_locks_per_relation configuration parameter** — [Lock Management](runtime-config-locks.md)
- **max_pred_locks_per_transaction configuration parameter** — [Lock Management](runtime-config-locks.md)
- **max_prepared_transactions configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **max_repack_replication_slots configuration parameter** — [Sending Servers](runtime-config-replication.md#runtime-config-replication-sender)
- **max_replication_slots configuration parameter** — [Sending Servers](runtime-config-replication.md#runtime-config-replication-sender)
- **max_slot_wal_keep_size configuration parameter** — [Sending Servers](runtime-config-replication.md#runtime-config-replication-sender)
- **max_stack_depth configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **max_standby_archive_delay configuration parameter** — [Standby Servers](runtime-config-replication.md#runtime-config-replication-standby)
- **max_standby_streaming_delay configuration parameter** — [Standby Servers](runtime-config-replication.md#runtime-config-replication-standby)
- **max_sync_workers_per_subscription configuration parameter** — [Subscribers](runtime-config-replication.md#runtime-config-replication-subscriber)
- **max_wal_senders configuration parameter** — [Sending Servers](runtime-config-replication.md#runtime-config-replication-sender)
- **max_wal_size configuration parameter** — [Checkpoints](runtime-config-wal.md#runtime-config-wal-checkpoints)
- **max_worker_processes configuration parameter** — [Worker Processes](runtime-config-resource.md#runtime-config-resource-worker-processes)
- **md5** — [String Functions and Operators](functions-string.md), [Binary String Functions and Operators](functions-binarystring.md)
- **MD5** — [Password Authentication](auth-password.md)
- **md5_password_warnings configuration parameter** — [Authentication](runtime-config-connection.md#runtime-config-connection-authentication)
- **median** — [Aggregate Expressions](sql-expressions.md#syntax-aggregates); *see also* percentile
- **memory context**
  - in SPI — [Memory Management](spi-memory.md)
- **memory overcommit** — [Linux Memory Overcommit](kernel-resources.md#linux-memory-overcommit)
- **MERGE** — [MERGE](sql-merge.md)
  - RETURNING — [Returning Data from Modified Rows](dml-returning.md), [Merge Support Functions](functions-merge-support.md)
- **merge_action** — [Merge Support Functions](functions-merge-support.md)
- **Meson** — [Requirements](install-requirements.md)
- **metaphone** — [Metaphone](fuzzystrmatch.md#fuzzystrmatch-metaphone)
- **min** — [Aggregate Functions](functions-aggregate.md)
- **MinGW**
  - installation on — [MinGW](installation-platform-notes.md#installation-notes-mingw)
- **min_dynamic_shared_memory configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **min_eager_agg_group_size configuration parameter** — [Planner Cost Constants](runtime-config-query.md#runtime-config-query-constants)
- **min_parallel_index_scan_size configuration parameter** — [Planner Cost Constants](runtime-config-query.md#runtime-config-query-constants)
- **min_parallel_table_scan_size configuration parameter** — [Planner Cost Constants](runtime-config-query.md#runtime-config-query-constants)
- **min_scale** — [Mathematical Functions and Operators](functions-math.md)
- **min_wal_size configuration parameter** — [Checkpoints](runtime-config-wal.md#runtime-config-wal-checkpoints)
- **mod** — [Mathematical Functions and Operators](functions-math.md)
- **mode**
  - statistical — [Aggregate Functions](functions-aggregate.md)
- **monitoring**
  - database activity — [Monitoring Database Activity](monitoring.md)
- **MOVE** — [MOVE](sql-move.md)
- **moving-aggregate mode** — [Moving-Aggregate Mode](xaggr.md#xaggr-moving-aggregates)
- **multirange (function)** — [Range/Multirange Functions and Operators](functions-range.md)
- **multirange type** — [Range Types](rangetypes.md)
- **multirange_minus_multi** — [Range/Multirange Functions and Operators](functions-range.md)
- **Multiversion Concurrency Control** — [Introduction](mvcc-intro.md)
- **MultiXactId** — [Multixacts and Wraparound](routine-vacuuming.md#vacuum-for-multixact-wraparound)
- **multixact_member_buffers configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **multixact_offset_buffers configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **MVCC** — [Introduction](mvcc-intro.md)
- **mxid_age** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)

## N

- **name**
  - qualified — [Creating a Schema](ddl-schemas.md#ddl-schemas-create)
  - syntax of — [Identifiers and Key Words](sql-syntax-lexical.md#sql-syntax-identifiers)
  - unqualified — [The Schema Search Path](ddl-schemas.md#ddl-schemas-path)
- **NaN** — *see* not a number
- **natural join** — [Joined Tables](queries-table-expressions.md#queries-join)
- **negation** — [Logical Operators](functions-logical.md)
- **NetBSD**
  - IPC configuration — [Shared Memory and Semaphores](kernel-resources.md#sysvipc)
  - shared library — [Compiling and Linking Dynamically-Loaded Functions](xfunc-c.md#dfunc)
  - start script — [Starting the Database Server](server-start.md)
- **netmask** — [Network Address Functions and Operators](functions-net.md)
- **network** — [Network Address Functions and Operators](functions-net.md)
  - data types — [Network Address Types](datatype-net-types.md)
- **nextval** — [Sequence Manipulation Functions](functions-sequence.md)
- **NFS** — [NFS](creating-cluster.md#creating-cluster-nfs)
- **nlevel** — [Operators and Functions](ltree.md#ltree-ops-funcs)
- **non-durable** — [Non-Durable Settings](non-durability.md)
- **nonblocking connection** — [Database Connection Control Functions](libpq-connect.md), [Database Connection Control Functions](libpq-connect.md), [Asynchronous Command Processing](libpq-async.md)
- **nonrepeatable read** — [Transaction Isolation](transaction-iso.md)
- **normalize** — [String Functions and Operators](functions-string.md)
- **normalized** — [String Functions and Operators](functions-string.md)
- **normal_rand** — [`normal_rand`](tablefunc.md#tablefunc-functions-normal-rand)
- **NOT (operator)** — [Logical Operators](functions-logical.md)
- **not a number**
  - floating point — [Floating-Point Types](datatype-numeric.md#datatype-float)
  - numeric (data type) — [Arbitrary Precision Numbers](datatype-numeric.md#datatype-numeric-decimal)
- **NOT IN** — [Subquery Expressions](functions-subquery.md), [Row and Array Comparisons](functions-comparisons.md)
- **not-null constraint** — [Not-Null Constraints](ddl-constraints.md#ddl-constraints-not-null)
- **notation**
  - functions — [Calling Functions](sql-syntax-calling-funcs.md)
- **notice processing**
  - in libpq — [Notice Processing](libpq-notice-processing.md)
- **notice processor** — [Notice Processing](libpq-notice-processing.md)
- **notice receiver** — [Notice Processing](libpq-notice-processing.md)
- **NOTIFY** — [NOTIFY](sql-notify.md)
  - in libpq — [Asynchronous Notification](libpq-notify.md)
- **notify_buffers configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **NOTNULL** — [Comparison Functions and Operators](functions-comparison.md)
- **now** — [Date/Time Functions and Operators](functions-datetime.md)
- **npoints** — [Geometric Functions and Operators](functions-geometry.md)
- **nth_value** — [Window Functions](functions-window.md)
- **ntile** — [Window Functions](functions-window.md)
- **null value**
  - with check constraints — [Check Constraints](ddl-constraints.md#ddl-constraints-check-constraints)
  - comparing — [Comparison Functions and Operators](functions-comparison.md)
  - default value — [Default Values](ddl-default.md)
  - in DISTINCT — [`DISTINCT`](queries-select-lists.md#queries-distinct)
  - in libpq — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
  - in PL/Perl — [PL/Perl Functions and Arguments](plperl-funcs.md)
  - in PL/Python — [Null, None](plpython-data.md#plpython-data-null)
  - with unique constraints — [Unique Constraints](ddl-constraints.md#ddl-constraints-unique-constraints)
- **NULLIF** — [`NULLIF`](functions-conditional.md#functions-nullif)
- **number**
  - constant — [Numeric Constants](sql-syntax-lexical.md#sql-syntax-constants-numeric)
- **numeric** — [Numeric Constants](sql-syntax-lexical.md#sql-syntax-constants-numeric)
- **numeric (data type)** — [Arbitrary Precision Numbers](datatype-numeric.md#datatype-numeric-decimal)
- **numnode** — [Text Search Functions and Operators](functions-textsearch.md), [Manipulating Queries](textsearch-features.md#textsearch-manipulate-tsquery)
- **num_nonnulls** — [Comparison Functions and Operators](functions-comparison.md)
- **num_nulls** — [Comparison Functions and Operators](functions-comparison.md)
- **num_os_semaphores configuration parameter** — [Preset Options](runtime-config-preset.md)
- **NVL** — [`COALESCE`](functions-conditional.md#functions-coalesce-nvl-ifnull)

## O

- **OAuth Authorization/Authentication** — [OAuth Authorization/Authentication](auth-oauth.md)
- **OAuth Validators** — [OAuth Validator Modules](oauth-validators.md)
- **oauth_validator_libraries configuration parameter** — [Authentication](runtime-config-connection.md#runtime-config-connection-authentication)
- **object identifier**
  - data type — [Object Identifier Types](datatype-oid.md)
- **object-oriented database** — [Concepts](tutorial-concepts.md)
- **obj_description** — [Comment Information Functions](functions-info.md#functions-info-comment)
- **OCCURRENCES_REGEX** — [Differences from SQL Standard and XQuery](functions-matching.md#posix-vs-xquery)
- **octet_length** — [String Functions and Operators](functions-string.md), [String Functions and Operators](functions-string.md), [Binary String Functions and Operators](functions-binarystring.md), [Bit String Functions and Operators](functions-bitstring.md)
- **OFFSET** — [`LIMIT` and `OFFSET`](queries-limit.md)
- **oid** — [Object Identifier Types](datatype-oid.md)
- **OID**
  - in libpq — [Retrieving Other Result Information](libpq-exec.md#libpq-exec-nonselect)
- **oid2name** — [oid2name](oid2name.md)
- **oid8** — [Object Identifier Types](datatype-oid.md)
- **ON CONFLICT** — [`ON CONFLICT` Clause](sql-insert.md#sql-on-conflict)
- **ONLY** — [The `FROM` Clause](queries-table-expressions.md#queries-from)
- **OOM** — [Linux Memory Overcommit](kernel-resources.md#linux-memory-overcommit)
- **OpenBSD**
  - IPC configuration — [Shared Memory and Semaphores](kernel-resources.md#sysvipc)
  - shared library — [Compiling and Linking Dynamically-Loaded Functions](xfunc-c.md#dfunc)
  - start script — [Starting the Database Server](server-start.md)
- **OpenSSL** — [PostgreSQL Features](install-make.md#configure-options-features), [PostgreSQL Features](install-meson.md#meson-options-features); *see also* SSL; *see also* SSL
- **operator** — [Functions and Operators](functions.md)
  - invocation — [Operator Invocations](sql-expressions.md#sql-expressions-operator-calls)
  - logical — [Logical Operators](functions-logical.md)
  - precedence — [Operator Precedence](sql-syntax-lexical.md#sql-precedence)
  - syntax — [Operators](sql-syntax-lexical.md#sql-syntax-operators)
  - type resolution in an invocation — [Operators](typeconv-oper.md)
  - user-defined — [User-Defined Operators](xoper.md)
- **operator class** — [Operator Classes and Operator Families](indexes-opclass.md), [Index Methods and Operator Classes](xindex.md#xindex-opclass)
- **operator family** — [Operator Classes and Operator Families](indexes-opclass.md), [Operator Classes and Operator Families](xindex.md#xindex-opfamily)
- **optimization information**
  - for functions — [Function Optimization Information](xfunc-optimization.md)
  - for operators — [Operator Optimization Information](xoper-optimization.md)
- **OR (operator)** — [Logical Operators](functions-logical.md)
- **Oracle**
  - porting from PL/SQL to PL/pgSQL — [Porting from Oracle PL/SQL](plpgsql-porting.md)
- **ORDER BY** — [Querying a Table](tutorial-select.md), [Sorting Rows (`ORDER BY`)](queries-order.md)
  - and locales — [Behavior](locale.md#locale-behavior)
- **ordered-set aggregate** — [Aggregate Expressions](sql-expressions.md#syntax-aggregates)
  - built-in — [Aggregate Functions](functions-aggregate.md)
- **ordering operator** — [System Dependencies on Operator Classes](xindex.md#xindex-opclass-dependencies)
- **ordinality** — [Set Returning Functions](functions-srf.md)
- **outer join** — [Joined Tables](queries-table-expressions.md#queries-join)
- **output function** — [User-Defined Types](xtypes.md)
- **OVER clause** — [Window Function Calls](sql-expressions.md#syntax-window-functions)
- **overcommit** — [Linux Memory Overcommit](kernel-resources.md#linux-memory-overcommit)
- **OVERLAPS** — [Date/Time Functions and Operators](functions-datetime.md)
- **overlay** — [String Functions and Operators](functions-string.md), [Binary String Functions and Operators](functions-binarystring.md), [Bit String Functions and Operators](functions-bitstring.md)
- **overloading**
  - functions — [Function Overloading](xfunc-overload.md)
  - operators — [User-Defined Operators](xoper.md)
- **owner** — [Privileges](ddl-priv.md)

## P

- **pageinspect** — [pageinspect — low-level inspection of database pages](pageinspect.md)
- **pages_per_range storage parameter** — [Index Storage Parameters](sql-createindex.md#sql-createindex-storage-parameters)
- **page_checksum** — [General Functions](pageinspect.md#pageinspect-general-funcs)
- **page_header** — [General Functions](pageinspect.md#pageinspect-general-funcs)
- **palloc** — [Writing Code](xfunc-c.md#xfunc-c-code)
- **PAM** — [PostgreSQL Features](install-make.md#configure-options-features), [PostgreSQL Features](install-meson.md#meson-options-features), [PAM Authentication](auth-pam.md)
- **parallel query** — [Parallel Query](parallel-query.md)
- **parallel_leader_participation configuration parameter** — [Worker Processes](runtime-config-resource.md#runtime-config-resource-worker-processes)
- **parallel_setup_cost configuration parameter** — [Planner Cost Constants](runtime-config-query.md#runtime-config-query-constants)
- **parallel_tuple_cost configuration parameter** — [Planner Cost Constants](runtime-config-query.md#runtime-config-query-constants)
- **parallel_workers storage parameter** — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **parameter**
  - syntax — [Positional Parameters](sql-expressions.md#sql-expressions-parameters-positional)
- **parenthesis** — [Value Expressions](sql-expressions.md)
- **parse_ident** — [String Functions and Operators](functions-string.md)
- **partition pruning** — [Partition Pruning](ddl-partitioning.md#ddl-partition-pruning)
- **partitioned table** — [Table Partitioning](ddl-partitioning.md)
- **partitioning** — [Table Partitioning](ddl-partitioning.md)
- **password** — [Role Attributes](role-attributes.md)
  - authentication — [Password Authentication](auth-password.md)
  - of the superuser — [Creating a Database Cluster](creating-cluster.md)
- **password file** — [The Password File](libpq-pgpass.md)
- **passwordcheck** — [passwordcheck — verify password strength](passwordcheck.md)
- **passwordcheck.min_password_length configuration parameter** — [Configuration Parameters](passwordcheck.md#passwordcheck-configuration-parameters)
- **password_encryption configuration parameter** — [Authentication](runtime-config-connection.md#runtime-config-connection-authentication)
- **password_expiration_warning_threshold configuration parameter** — [Authentication](runtime-config-connection.md#runtime-config-connection-authentication)
- **path** — [Geometric Functions and Operators](functions-geometry.md)
  - for schemas — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **PATH** — [Environment Variables](install-post.md#install-post-env-vars)
- **path (data type)** — [Paths](datatype-geometric.md#datatype-geometric-paths)
- **pattern matching** — [Pattern Matching](functions-matching.md)
- **patterns**
  - in psql and pg_dump — [Patterns](app-psql.md#app-psql-patterns)
- **pclose** — [Geometric Functions and Operators](functions-geometry.md)
- **peer** — [Peer Authentication](auth-peer.md)
- **percentile**
  - continuous — [Aggregate Functions](functions-aggregate.md)
  - discrete — [Aggregate Functions](functions-aggregate.md)
- **percent_rank** — [Window Functions](functions-window.md)
  - hypothetical — [Aggregate Functions](functions-aggregate.md)
- **performance** — [Performance Tips](performance-tips.md)
- **perl** — [Requirements](install-requirements.md)
- **Perl** — [PL/Perl — Perl Procedural Language](plperl.md)
- **permission** — *see* privilege
- **pfree** — [Writing Code](xfunc-c.md#xfunc-c-code)
- **PGAPPNAME** — [Environment Variables](libpq-envars.md)
- **pgbench** — [pgbench](pgbench.md)
- **PGcancel** — [Obsolete Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-deprecated)
- **PGcancelConn** — [Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-functions)
- **PGCHANNELBINDING** — [Environment Variables](libpq-envars.md)
- **PGCLIENTENCODING** — [Environment Variables](libpq-envars.md)
- **PGconn** — [Database Connection Control Functions](libpq-connect.md)
- **PGCONNECT_TIMEOUT** — [Environment Variables](libpq-envars.md)
- **pgcrypto** — [pgcrypto — cryptographic functions](pgcrypto.md)
- **pgcrypto.builtin_crypto_enabled configuration
      parameter** — [Configuration Parameters](pgcrypto.md#pgcrypto-configuration-parameters)
- **PGDATA** — [Creating a Database Cluster](creating-cluster.md)
- **PGDATABASE** — [Environment Variables](libpq-envars.md)
- **PGDATESTYLE** — [Environment Variables](libpq-envars.md)
- **PGEventProc** — [Event Callback Procedure](libpq-events.md#libpq-events-proc)
- **PGGEQO** — [Environment Variables](libpq-envars.md)
- **PGGSSDELEGATION** — [Environment Variables](libpq-envars.md)
- **PGGSSENCMODE** — [Environment Variables](libpq-envars.md)
- **PGGSSLIB** — [Environment Variables](libpq-envars.md)
- **PGHOST** — [Environment Variables](libpq-envars.md)
- **PGHOSTADDR** — [Environment Variables](libpq-envars.md)
- **PGKRBSRVNAME** — [Environment Variables](libpq-envars.md)
- **PGLOADBALANCEHOSTS** — [Environment Variables](libpq-envars.md)
- **PGLOCALEDIR** — [Environment Variables](libpq-envars.md)
- **PGMAXPROTOCOLVERSION** — [Environment Variables](libpq-envars.md)
- **PGMINPROTOCOLVERSION** — [Environment Variables](libpq-envars.md)
- **PGOAUTHCAFILE** — [Environment Variables](libpq-envars.md)
- **PGOPTIONS** — [Environment Variables](libpq-envars.md)
- **pgoutput** — [pgoutput — Standard Logical Decoding Output Plugin](logicaldecoding-output-plugin.md#logicaldecoding-pgoutput)
- **PGPASSFILE** — [Environment Variables](libpq-envars.md)
- **PGPASSWORD** — [Environment Variables](libpq-envars.md)
- **PGPORT** — [Environment Variables](libpq-envars.md)
- **pgp_armor_headers** — [`pgp_armor_headers`](pgcrypto.md#pgcrypto-pgp-enc-funcs-pgp-armor-headers)
- **pgp_key_id** — [`pgp_key_id()`](pgcrypto.md#pgcrypto-pgp-enc-funcs-pgp-key-id)
- **pgp_pub_decrypt** — [`pgp_pub_decrypt()`](pgcrypto.md#pgcrypto-pgp-enc-funcs-pgp-pub-decrypt)
- **pgp_pub_decrypt_bytea** — [`pgp_pub_decrypt()`](pgcrypto.md#pgcrypto-pgp-enc-funcs-pgp-pub-decrypt)
- **pgp_pub_encrypt** — [`pgp_pub_encrypt()`](pgcrypto.md#pgcrypto-pgp-enc-funcs-pgp-pub-encrypt)
- **pgp_pub_encrypt_bytea** — [`pgp_pub_encrypt()`](pgcrypto.md#pgcrypto-pgp-enc-funcs-pgp-pub-encrypt)
- **pgp_sym_decrypt** — [`pgp_sym_decrypt()`](pgcrypto.md#pgcrypto-pgp-enc-funcs-pgp-sym-decrypt)
- **pgp_sym_decrypt_bytea** — [`pgp_sym_decrypt()`](pgcrypto.md#pgcrypto-pgp-enc-funcs-pgp-sym-decrypt)
- **pgp_sym_encrypt** — [`pgp_sym_encrypt()`](pgcrypto.md#pgcrypto-pgp-enc-funcs-pgp-sym-encrypt)
- **pgp_sym_encrypt_bytea** — [`pgp_sym_encrypt()`](pgcrypto.md#pgcrypto-pgp-enc-funcs-pgp-sym-encrypt)
- **PGREQUIREAUTH** — [Environment Variables](libpq-envars.md)
- **PGREQUIREPEER** — [Environment Variables](libpq-envars.md)
- **PGREQUIRESSL** — [Environment Variables](libpq-envars.md)
- **PGresult** — [Main Functions](libpq-exec.md#libpq-exec-main)
- **pgrowlocks** — [pgrowlocks — show a table's row locking information](pgrowlocks.md), [Overview](pgrowlocks.md#pgrowlocks-overview)
- **PGSERVICE** — [Environment Variables](libpq-envars.md)
- **PGSERVICEFILE** — [Environment Variables](libpq-envars.md)
- **PGSSLCERT** — [Environment Variables](libpq-envars.md)
- **PGSSLCERTMODE** — [Environment Variables](libpq-envars.md)
- **PGSSLCOMPRESSION** — [Environment Variables](libpq-envars.md)
- **PGSSLCRL** — [Environment Variables](libpq-envars.md)
- **PGSSLCRLDIR** — [Environment Variables](libpq-envars.md)
- **PGSSLKEY** — [Environment Variables](libpq-envars.md)
- **PGSSLMAXPROTOCOLVERSION** — [Environment Variables](libpq-envars.md)
- **PGSSLMINPROTOCOLVERSION** — [Environment Variables](libpq-envars.md)
- **PGSSLMODE** — [Environment Variables](libpq-envars.md)
- **PGSSLNEGOTIATION** — [Environment Variables](libpq-envars.md)
- **PGSSLROOTCERT** — [Environment Variables](libpq-envars.md)
- **PGSSLSNI** — [Environment Variables](libpq-envars.md)
- **pgstatginindex** — [Functions](pgstattuple.md#pgstattuple-funcs)
- **pgstathashindex** — [Functions](pgstattuple.md#pgstattuple-funcs)
- **pgstatindex** — [Functions](pgstattuple.md#pgstattuple-funcs)
- **pgstattuple** — [pgstattuple — obtain tuple-level statistics](pgstattuple.md), [Functions](pgstattuple.md#pgstattuple-funcs)
- **pgstattuple_approx** — [Functions](pgstattuple.md#pgstattuple-funcs)
- **PGSYSCONFDIR** — [Environment Variables](libpq-envars.md)
- **PGTARGETSESSIONATTRS** — [Environment Variables](libpq-envars.md)
- **PGTZ** — [Environment Variables](libpq-envars.md)
- **PGUSER** — [Environment Variables](libpq-envars.md)
- **pgxs** — [Extension Building Infrastructure](extend-pgxs.md)
- **pg_advisory_lock** — [Advisory Lock Functions](functions-admin.md#functions-advisory-locks)
- **pg_advisory_lock_shared** — [Advisory Lock Functions](functions-admin.md#functions-advisory-locks)
- **pg_advisory_unlock** — [Advisory Lock Functions](functions-admin.md#functions-advisory-locks)
- **pg_advisory_unlock_all** — [Advisory Lock Functions](functions-admin.md#functions-advisory-locks)
- **pg_advisory_unlock_shared** — [Advisory Lock Functions](functions-admin.md#functions-advisory-locks)
- **pg_advisory_xact_lock** — [Advisory Lock Functions](functions-admin.md#functions-advisory-locks)
- **pg_advisory_xact_lock_shared** — [Advisory Lock Functions](functions-admin.md#functions-advisory-locks)
- **pg_aggregate** — [pg_aggregate](catalog-pg-aggregate.md)
- **pg_aios** — [pg_aios](view-pg-aios.md)
- **pg_am** — [pg_am](catalog-pg-am.md)
- **pg_amcheck** — [pg_amcheck](app-pgamcheck.md)
- **pg_amop** — [pg_amop](catalog-pg-amop.md)
- **pg_amproc** — [pg_amproc](catalog-pg-amproc.md)
- **pg_archivecleanup** — [pg_archivecleanup](pgarchivecleanup.md)
- **pg_attrdef** — [pg_attrdef](catalog-pg-attrdef.md)
- **pg_attribute** — [pg_attribute](catalog-pg-attribute.md)
- **pg_authid** — [pg_authid](catalog-pg-authid.md)
- **pg_auth_members** — [pg_auth_members](catalog-pg-auth-members.md)
- **pg_available_extensions** — [pg_available_extensions](view-pg-available-extensions.md)
- **pg_available_extension_versions** — [pg_available_extension_versions](view-pg-available-extension-versions.md)
- **pg_available_wal_summaries** — [WAL Summarization Information Functions](functions-info.md#functions-info-wal-summary)
- **pg_backend_memory_contexts** — [pg_backend_memory_contexts](view-pg-backend-memory-contexts.md)
- **pg_backend_pid** — [Session Information Functions](functions-info.md#functions-info-session)
- **pg_backup_start** — [Backup Control Functions](functions-admin.md#functions-admin-backup)
- **pg_backup_stop** — [Backup Control Functions](functions-admin.md#functions-admin-backup)
- **pg_basebackup** — [pg_basebackup](app-pgbasebackup.md)
- **pg_basetype** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_blocking_pids** — [Session Information Functions](functions-info.md#functions-info-session)
- **pg_buffercache** — [pg_buffercache — inspect PostgreSQL buffer cache state](pgbuffercache.md)
- **pg_buffercache_evict** — [pg_buffercache — inspect PostgreSQL buffer cache state](pgbuffercache.md)
- **pg_buffercache_evict_all** — [pg_buffercache — inspect PostgreSQL buffer cache state](pgbuffercache.md)
- **pg_buffercache_evict_relation** — [pg_buffercache — inspect PostgreSQL buffer cache state](pgbuffercache.md)
- **pg_buffercache_mark_dirty** — [pg_buffercache — inspect PostgreSQL buffer cache state](pgbuffercache.md)
- **pg_buffercache_mark_dirty_all** — [pg_buffercache — inspect PostgreSQL buffer cache state](pgbuffercache.md)
- **pg_buffercache_mark_dirty_relation** — [pg_buffercache — inspect PostgreSQL buffer cache state](pgbuffercache.md)
- **pg_buffercache_numa** — [pg_buffercache — inspect PostgreSQL buffer cache state](pgbuffercache.md)
- **pg_buffercache_pages** — [pg_buffercache — inspect PostgreSQL buffer cache state](pgbuffercache.md)
- **pg_buffercache_summary** — [pg_buffercache — inspect PostgreSQL buffer cache state](pgbuffercache.md)
- **pg_buffercache_usage_counts** — [pg_buffercache — inspect PostgreSQL buffer cache state](pgbuffercache.md)
- **pg_cancel_backend** — [Server Signaling Functions](functions-admin.md#functions-admin-signal)
- **pg_cast** — [pg_cast](catalog-pg-cast.md)
- **pg_char_to_encoding** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_checksums** — [pg_checksums](app-pgchecksums.md)
- **pg_class** — [pg_class](catalog-pg-class.md)
- **pg_clear_attribute_stats** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_clear_extended_stats** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_clear_relation_stats** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_client_encoding** — [String Functions and Operators](functions-string.md)
- **pg_collation** — [pg_collation](catalog-pg-collation.md)
- **pg_collation_actual_version** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_collation_is_visible** — [Schema Visibility Inquiry Functions](functions-info.md#functions-info-schema)
- **PG_COLOR** — [When Color is Used](color-when.md)
- **PG_COLORS** — [Configuring the Colors](color-which.md)
- **pg_column_compression** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_column_size** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_column_toast_chunk_id** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_combinebackup** — [pg_combinebackup](app-pgcombinebackup.md)
- **pg_config** — [pg_config](app-pgconfig.md), [pg_config](view-pg-config.md)
  - with
   ecpg — [Processing Embedded SQL Programs](ecpg-process.md)
  - with libpq — [Building libpq Programs](libpq-build.md)
  - with user-defined C functions — [Writing Code](xfunc-c.md#xfunc-c-code)
- **pg_conf_load_time** — [Session Information Functions](functions-info.md#functions-info-session)
- **pg_constraint** — [pg_constraint](catalog-pg-constraint.md)
- **pg_controldata** — [pg_controldata](app-pgcontroldata.md)
- **pg_control_checkpoint** — [Control Data Functions](functions-info.md#functions-info-controldata)
- **pg_control_init** — [Control Data Functions](functions-info.md#functions-info-controldata)
- **pg_control_recovery** — [Control Data Functions](functions-info.md#functions-info-controldata)
- **pg_control_system** — [Control Data Functions](functions-info.md#functions-info-controldata)
- **pg_conversion** — [pg_conversion](catalog-pg-conversion.md)
- **pg_conversion_is_visible** — [Schema Visibility Inquiry Functions](functions-info.md#functions-info-schema)
- **pg_copy_logical_replication_slot** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_copy_physical_replication_slot** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_createsubscriber** — [pg_createsubscriber](app-pgcreatesubscriber.md)
- **pg_create_advice_stash** — [Functions](pgstashadvice.md#pgstashadvice-functions)
- **pg_create_logical_replication_slot** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_create_physical_replication_slot** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_create_restore_point** — [Backup Control Functions](functions-admin.md#functions-admin-backup)
- **pg_ctl** — [Creating a Database Cluster](creating-cluster.md), [Starting the Database Server](server-start.md), [pg_ctl](app-pg-ctl.md)
- **pg_current_logfile** — [Session Information Functions](functions-info.md#functions-info-session)
- **pg_current_snapshot** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **pg_current_wal_flush_lsn** — [Backup Control Functions](functions-admin.md#functions-admin-backup)
- **pg_current_wal_insert_lsn** — [Backup Control Functions](functions-admin.md#functions-admin-backup)
- **pg_current_wal_lsn** — [Backup Control Functions](functions-admin.md#functions-admin-backup)
- **pg_current_xact_id** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **pg_current_xact_id_if_assigned** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **pg_cursors** — [pg_cursors](view-pg-cursors.md)
- **pg_database** — [Template Databases](manage-ag-templatedbs.md), [pg_database](catalog-pg-database.md)
- **pg_database_collation_actual_version** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_database_size** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_db_role_setting** — [pg_db_role_setting](catalog-pg-db-role-setting.md)
- **pg_ddl_command** — [Pseudo-Types](datatype-pseudo.md)
- **pg_default_acl** — [pg_default_acl](catalog-pg-default-acl.md)
- **pg_depend** — [pg_depend](catalog-pg-depend.md)
- **pg_describe_object** — [Object Information and Addressing Functions](functions-info.md#functions-info-object)
- **pg_description** — [pg_description](catalog-pg-description.md)
- **pg_disable_data_checksums** — [Data Checksum Functions](functions-admin.md#functions-admin-checksum)
- **pg_drop_advice_stash** — [Functions](pgstashadvice.md#pgstashadvice-functions)
- **pg_drop_replication_slot** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_dsm_registry_allocations** — [pg_dsm_registry_allocations](view-pg-dsm-registry-allocations.md)
- **pg_dump** — [pg_dump](app-pgdump.md)
- **pg_dumpall** — [pg_dumpall](app-pg-dumpall.md)
  - use during upgrade — [Upgrading Data via pg_dumpall](upgrading.md#upgrading-via-pgdumpall)
- **pg_enable_data_checksums** — [Data Checksum Functions](functions-admin.md#functions-admin-checksum)
- **pg_encoding_to_char** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_enum** — [pg_enum](catalog-pg-enum.md)
- **pg_event_trigger** — [pg_event_trigger](catalog-pg-event-trigger.md)
- **pg_event_trigger_ddl_commands** — [Capturing Changes at Command End](functions-event-triggers.md#pg-event-trigger-ddl-command-end-functions)
- **pg_event_trigger_dropped_objects** — [Processing Objects Dropped by a DDL Command](functions-event-triggers.md#pg-event-trigger-sql-drop-functions)
- **pg_event_trigger_table_rewrite_oid** — [Handling a Table Rewrite Event](functions-event-triggers.md#pg-event-trigger-table-rewrite-functions)
- **pg_event_trigger_table_rewrite_reason** — [Handling a Table Rewrite Event](functions-event-triggers.md#pg-event-trigger-table-rewrite-functions)
- **pg_export_snapshot** — [Snapshot Synchronization Functions](functions-admin.md#functions-snapshot-synchronization)
- **pg_extension** — [pg_extension](catalog-pg-extension.md)
- **pg_extension_config_dump** — [Extension Configuration Tables](extend-extensions.md#extend-extensions-config-tables)
- **pg_filenode_relation** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_file_settings** — [pg_file_settings](view-pg-file-settings.md)
- **pg_foreign_data_wrapper** — [pg_foreign_data_wrapper](catalog-pg-foreign-data-wrapper.md)
- **pg_foreign_server** — [pg_foreign_server](catalog-pg-foreign-server.md)
- **pg_foreign_table** — [pg_foreign_table](catalog-pg-foreign-table.md)
- **pg_freespace** — [Functions](pgfreespacemap.md#pgfreespacemap-funcs)
- **pg_freespacemap** — [pg_freespacemap — examine the free space map](pgfreespacemap.md)
- **pg_function_is_visible** — [Schema Visibility Inquiry Functions](functions-info.md#functions-info-schema)
- **pg_get_acl** — [Object Information and Addressing Functions](functions-info.md#functions-info-object)
- **pg_get_advice_stashes** — [Functions](pgstashadvice.md#pgstashadvice-functions)
- **pg_get_advice_stash_contents** — [Functions](pgstashadvice.md#pgstashadvice-functions)
- **pg_get_catalog_foreign_keys** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_constraintdef** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_database_ddl** — [Get Object DDL Functions](functions-info.md#functions-get-object-ddl)
- **pg_get_expr** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_functiondef** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_function_arguments** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_function_identity_arguments** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_function_result** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_indexdef** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_keywords** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_loaded_modules** — [Session Information Functions](functions-info.md#functions-info-session)
- **pg_get_multixact_members** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **pg_get_multixact_stats** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **pg_get_object_address** — [Object Information and Addressing Functions](functions-info.md#functions-info-object)
- **pg_get_partition_constraintdef** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_partkeydef** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_propgraphdef** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_role_ddl** — [Get Object DDL Functions](functions-info.md#functions-get-object-ddl)
- **pg_get_ruledef** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_sequence_data** — [Sequence Manipulation Functions](functions-sequence.md)
- **pg_get_serial_sequence** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_statisticsobjdef** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_tablespace_ddl** — [Get Object DDL Functions](functions-info.md#functions-get-object-ddl)
- **pg_get_triggerdef** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_userbyid** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_viewdef** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_get_wal_replay_pause_state** — [Recovery Control Functions](functions-admin.md#functions-recovery-control)
- **pg_get_wal_resource_managers** — [Recovery Control Functions](functions-admin.md#functions-recovery-control)
- **pg_get_wal_summarizer_state** — [WAL Summarization Information Functions](functions-info.md#functions-info-wal-summary)
- **pg_group** — [pg_group](view-pg-group.md)
- **pg_has_role** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **pg_hba.conf** — [The `pg_hba.conf` File](auth-pg-hba-conf.md)
- **pg_hba_file_rules** — [pg_hba_file_rules](view-pg-hba-file-rules.md)
- **pg_ident.conf** — [User Name Maps](auth-username-maps.md)
- **pg_identify_object** — [Object Information and Addressing Functions](functions-info.md#functions-info-object)
- **pg_identify_object_as_address** — [Object Information and Addressing Functions](functions-info.md#functions-info-object)
- **pg_ident_file_mappings** — [pg_ident_file_mappings](view-pg-ident-file-mappings.md)
- **pg_import_system_collations** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_index** — [pg_index](catalog-pg-index.md)
- **pg_indexam_has_property** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_indexes** — [pg_indexes](view-pg-indexes.md)
- **pg_indexes_size** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_index_column_has_property** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_index_has_property** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_inherits** — [pg_inherits](catalog-pg-inherits.md)
- **pg_init_privs** — [pg_init_privs](catalog-pg-init-privs.md)
- **pg_input_error_info** — [Data Validity Checking Functions](functions-info.md#functions-info-validity)
- **pg_input_is_valid** — [Data Validity Checking Functions](functions-info.md#functions-info-validity)
- **pg_isready** — [pg_isready](app-pg-isready.md)
- **pg_is_in_recovery** — [Recovery Control Functions](functions-admin.md#functions-recovery-control)
- **pg_is_other_temp_schema** — [Session Information Functions](functions-info.md#functions-info-session)
- **pg_is_wal_replay_paused** — [Recovery Control Functions](functions-admin.md#functions-recovery-control)
- **pg_jit_available** — [Session Information Functions](functions-info.md#functions-info-session)
- **pg_language** — [pg_language](catalog-pg-language.md)
- **pg_largeobject** — [pg_largeobject](catalog-pg-largeobject.md)
- **pg_largeobject_metadata** — [pg_largeobject_metadata](catalog-pg-largeobject-metadata.md)
- **pg_last_committed_xact** — [Committed Transaction Information Functions](functions-info.md#functions-info-commit-timestamp)
- **pg_last_wal_receive_lsn** — [Recovery Control Functions](functions-admin.md#functions-recovery-control)
- **pg_last_wal_replay_lsn** — [Recovery Control Functions](functions-admin.md#functions-recovery-control)
- **pg_last_xact_replay_timestamp** — [Recovery Control Functions](functions-admin.md#functions-recovery-control)
- **pg_listening_channels** — [Session Information Functions](functions-info.md#functions-info-session)
- **pg_locks** — [pg_locks](view-pg-locks.md)
- **pg_logicalinspect** — [pg_logicalinspect — logical decoding components inspection](pglogicalinspect.md)
- **pg_logical_emit_message** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_logical_slot_get_binary_changes** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_logical_slot_get_changes** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_logical_slot_peek_binary_changes** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_logical_slot_peek_changes** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_log_backend_memory_contexts** — [Server Signaling Functions](functions-admin.md#functions-admin-signal)
- **pg_log_standby_snapshot** — [Snapshot Synchronization Functions](functions-admin.md#functions-snapshot-synchronization)
- **pg_lsn** — [`pg_lsn` Type](datatype-pg-lsn.md)
- **pg_ls_archive_statusdir** — [Generic File Access Functions](functions-admin.md#functions-admin-genfile)
- **pg_ls_dir** — [Generic File Access Functions](functions-admin.md#functions-admin-genfile)
- **pg_ls_logdir** — [Generic File Access Functions](functions-admin.md#functions-admin-genfile)
- **pg_ls_logicalmapdir** — [Generic File Access Functions](functions-admin.md#functions-admin-genfile)
- **pg_ls_logicalsnapdir** — [Generic File Access Functions](functions-admin.md#functions-admin-genfile)
- **pg_ls_replslotdir** — [Generic File Access Functions](functions-admin.md#functions-admin-genfile)
- **pg_ls_summariesdir** — [Generic File Access Functions](functions-admin.md#functions-admin-genfile)
- **pg_ls_tmpdir** — [Generic File Access Functions](functions-admin.md#functions-admin-genfile)
- **pg_ls_waldir** — [Generic File Access Functions](functions-admin.md#functions-admin-genfile)
- **pg_matviews** — [pg_matviews](view-pg-matviews.md)
- **pg_mcv_list_items** — [Inspecting MCV Lists](functions-statistics.md#functions-statistics-mcv)
- **PG_MODULE_MAGIC** — [Dynamic Loading](xfunc-c.md#xfunc-c-dynload)
- **pg_my_temp_schema** — [Session Information Functions](functions-info.md#functions-info-session)
- **pg_namespace** — [pg_namespace](catalog-pg-namespace.md)
- **pg_notification_queue_usage** — [Session Information Functions](functions-info.md#functions-info-session)
- **pg_notify** — [pg_notify](sql-notify.md#id-1.9.3.161.7.5)
- **pg_numa_available** — [Session Information Functions](functions-info.md#functions-info-session)
- **pg_opclass** — [pg_opclass](catalog-pg-opclass.md)
- **pg_opclass_is_visible** — [Schema Visibility Inquiry Functions](functions-info.md#functions-info-schema)
- **pg_operator** — [pg_operator](catalog-pg-operator.md)
- **pg_operator_is_visible** — [Schema Visibility Inquiry Functions](functions-info.md#functions-info-schema)
- **pg_opfamily** — [pg_opfamily](catalog-pg-opfamily.md)
- **pg_opfamily_is_visible** — [Schema Visibility Inquiry Functions](functions-info.md#functions-info-schema)
- **pg_options_to_table** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_overexplain** — [pg_overexplain — allow EXPLAIN to dump even more details](pgoverexplain.md)
- **pg_parameter_acl** — [pg_parameter_acl](catalog-pg-parameter-acl.md)
- **pg_partitioned_table** — [pg_partitioned_table](catalog-pg-partitioned-table.md)
- **pg_partition_ancestors** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_partition_root** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_partition_tree** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_plan_advice** — [pg_plan_advice — help the planner get the right plan](pgplanadvice.md)
- **pg_plan_advice.advice configuration parameter** — [Configuration Parameters](pgplanadvice.md#pgplanadvice-config-params)
- **pg_plan_advice.always_explain_supplied_advice configuration parameter** — [Configuration Parameters](pgplanadvice.md#pgplanadvice-config-params)
- **pg_plan_advice.always_store_advice_details configuration parameter** — [Configuration Parameters](pgplanadvice.md#pgplanadvice-config-params)
- **pg_plan_advice.feedback_warnings configuration parameter** — [Configuration Parameters](pgplanadvice.md#pgplanadvice-config-params)
- **pg_plan_advice.trace_mask configuration parameter** — [Configuration Parameters](pgplanadvice.md#pgplanadvice-config-params)
- **pg_policies** — [pg_policies](view-pg-policies.md)
- **pg_policy** — [pg_policy](catalog-pg-policy.md)
- **pg_postmaster_start_time** — [Session Information Functions](functions-info.md#functions-info-session)
- **pg_prepared_statements** — [pg_prepared_statements](view-pg-prepared-statements.md)
- **pg_prepared_xacts** — [pg_prepared_xacts](view-pg-prepared-xacts.md)
- **pg_prewarm** — [pg_prewarm — preload relation data into buffer caches](pgprewarm.md)
- **pg_prewarm.autoprewarm configuration parameter** — [Configuration Parameters](pgprewarm.md#pgprewarm-config-params)
- **pg_prewarm.autoprewarm_interval configuration parameter** — [Configuration Parameters](pgprewarm.md#pgprewarm-config-params)
- **pg_proc** — [pg_proc](catalog-pg-proc.md)
- **pg_promote** — [Recovery Control Functions](functions-admin.md#functions-recovery-control)
- **pg_propgraph_element** — [pg_propgraph_element](catalog-pg-propgraph-element.md)
- **pg_propgraph_element_label** — [pg_propgraph_element_label](catalog-pg-propgraph-element-label.md)
- **pg_propgraph_label** — [pg_propgraph_label](catalog-pg-propgraph-label.md)
- **pg_propgraph_label_property** — [pg_propgraph_label_property](catalog-pg-propgraph-label-property.md)
- **pg_propgraph_property** — [pg_propgraph_property](catalog-pg-propgraph-property.md)
- **pg_publication** — [pg_publication](catalog-pg-publication.md)
- **pg_publication_namespace** — [pg_publication_namespace](catalog-pg-publication-namespace.md)
- **pg_publication_rel** — [pg_publication_rel](catalog-pg-publication-rel.md)
- **pg_publication_sequences** — [pg_publication_sequences](view-pg-publication-sequences.md)
- **pg_publication_tables** — [pg_publication_tables](view-pg-publication-tables.md)
- **pg_range** — [pg_range](catalog-pg-range.md)
- **pg_read_binary_file** — [Generic File Access Functions](functions-admin.md#functions-admin-genfile)
- **pg_read_file** — [Generic File Access Functions](functions-admin.md#functions-admin-genfile)
- **pg_receivewal** — [pg_receivewal](app-pgreceivewal.md)
- **pg_receivexlog** — [`pg_receivexlog` renamed to `pg_receivewal`](app-pgreceivexlog.md) — *see* pg_receivewal
- **pg_recvlogical** — [pg_recvlogical](app-pgrecvlogical.md)
- **pg_relation_filenode** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_relation_filepath** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_relation_size** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_reload_conf** — [Server Signaling Functions](functions-admin.md#functions-admin-signal)
- **pg_relpages** — [Functions](pgstattuple.md#pgstattuple-funcs)
- **pg_replication_origin** — [pg_replication_origin](catalog-pg-replication-origin.md)
- **pg_replication_origin_advance** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_replication_origin_create** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_replication_origin_drop** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_replication_origin_oid** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_replication_origin_progress** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_replication_origin_session_is_setup** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_replication_origin_session_progress** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_replication_origin_session_reset** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_replication_origin_session_setup** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_replication_origin_status** — [pg_replication_origin_status](view-pg-replication-origin-status.md)
- **pg_replication_origin_xact_reset** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_replication_origin_xact_setup** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_replication_slots** — [pg_replication_slots](view-pg-replication-slots.md)
- **pg_replication_slot_advance** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_resetwal** — [pg_resetwal](app-pgresetwal.md)
- **pg_resetxlog** — [`pg_resetxlog` renamed to `pg_resetwal`](app-pgresetxlog.md) — *see* pg_resetwal
- **pg_restore** — [pg_restore](app-pgrestore.md)
- **pg_restore_attribute_stats** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_restore_extended_stats** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_restore_relation_stats** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_rewind** — [pg_rewind](app-pgrewind.md)
- **pg_rewrite** — [pg_rewrite](catalog-pg-rewrite.md)
- **pg_roles** — [pg_roles](view-pg-roles.md)
- **pg_rotate_logfile** — [Server Signaling Functions](functions-admin.md#functions-admin-signal)
- **pg_rules** — [pg_rules](view-pg-rules.md)
- **pg_safe_snapshot_blocking_pids** — [Session Information Functions](functions-info.md#functions-info-session)
- **pg_seclabel** — [pg_seclabel](catalog-pg-seclabel.md)
- **pg_seclabels** — [pg_seclabels](view-pg-seclabels.md)
- **pg_sequence** — [pg_sequence](catalog-pg-sequence.md)
- **pg_sequences** — [pg_sequences](view-pg-sequences.md)
- **pg_service.conf** — [The Connection Service File](libpq-pgservice.md)
- **pg_settings** — [pg_settings](view-pg-settings.md)
- **pg_settings_get_flags** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_set_stashed_advice** — [Functions](pgstashadvice.md#pgstashadvice-functions)
- **pg_shadow** — [pg_shadow](view-pg-shadow.md)
- **pg_shdepend** — [pg_shdepend](catalog-pg-shdepend.md)
- **pg_shdescription** — [pg_shdescription](catalog-pg-shdescription.md)
- **pg_shmem_allocations** — [pg_shmem_allocations](view-pg-shmem-allocations.md)
- **pg_shmem_allocations_numa** — [pg_shmem_allocations_numa](view-pg-shmem-allocations-numa.md)
- **pg_shseclabel** — [pg_shseclabel](catalog-pg-shseclabel.md)
- **pg_size_bytes** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_size_pretty** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_sleep** — [Delaying Execution](functions-datetime.md#functions-datetime-delay)
- **pg_sleep_for** — [Delaying Execution](functions-datetime.md#functions-datetime-delay)
- **pg_sleep_until** — [Delaying Execution](functions-datetime.md#functions-datetime-delay)
- **pg_snapshot_xip** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **pg_snapshot_xmax** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **pg_snapshot_xmin** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **pg_split_walfile_name** — [Backup Control Functions](functions-admin.md#functions-admin-backup)
- **pg_start_stash_advice_worker** — [Functions](pgstashadvice.md#pgstashadvice-functions)
- **pg_stash_advice** — [pg_stash_advice — store and automatically apply plan advice](pgstashadvice.md)
- **pg_stash_advice.persist configuration parameter** — [Configuration Parameters](pgstashadvice.md#pgstashadvice-config-params)
- **pg_stash_advice.persist_interval configuration parameter** — [Configuration Parameters](pgstashadvice.md#pgstashadvice-config-params)
- **pg_stash_advice.stash_name configuration parameter** — [Configuration Parameters](pgstashadvice.md#pgstashadvice-config-params)
- **pg_statio_all_indexes** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_statio_all_indexes](monitoring-stats.md#monitoring-pg-statio-all-indexes-view)
- **pg_statio_all_sequences** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_statio_all_sequences](monitoring-stats.md#monitoring-pg-statio-all-sequences-view)
- **pg_statio_all_tables** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_statio_all_tables](monitoring-stats.md#monitoring-pg-statio-all-tables-view)
- **pg_statio_sys_indexes** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views)
- **pg_statio_sys_sequences** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views)
- **pg_statio_sys_tables** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views)
- **pg_statio_user_indexes** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views)
- **pg_statio_user_sequences** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views)
- **pg_statio_user_tables** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views)
- **pg_statistic** — [Single-Column Statistics](planner-stats.md#planner-stats-single-column), [pg_statistic](catalog-pg-statistic.md)
- **pg_statistics_obj_is_visible** — [Schema Visibility Inquiry Functions](functions-info.md#functions-info-schema)
- **pg_statistic_ext** — [Extended Statistics](planner-stats.md#planner-stats-extended), [pg_statistic_ext](catalog-pg-statistic-ext.md)
- **pg_statistic_ext_data** — [Extended Statistics](planner-stats.md#planner-stats-extended), [pg_statistic_ext_data](catalog-pg-statistic-ext-data.md)
- **pg_stats** — [Single-Column Statistics](planner-stats.md#planner-stats-single-column), [pg_stats](view-pg-stats.md)
- **pg_stats_ext** — [pg_stats_ext](view-pg-stats-ext.md)
- **pg_stats_ext_exprs** — [pg_stats_ext_exprs](view-pg-stats-ext-exprs.md)
- **pg_stat_activity** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_activity](monitoring-stats.md#monitoring-pg-stat-activity-view)
- **pg_stat_all_indexes** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_all_indexes](monitoring-stats.md#monitoring-pg-stat-all-indexes-view)
- **pg_stat_all_tables** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_all_tables](monitoring-stats.md#monitoring-pg-stat-all-tables-view)
- **pg_stat_archiver** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_archiver](monitoring-stats.md#monitoring-pg-stat-archiver-view)
- **pg_stat_autovacuum_scores** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_autovacuum_scores](monitoring-stats.md#monitoring-pg-stat-autovacuum-scores-view)
- **pg_stat_bgwriter** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_bgwriter](monitoring-stats.md#monitoring-pg-stat-bgwriter-view)
- **pg_stat_checkpointer** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_checkpointer](monitoring-stats.md#monitoring-pg-stat-checkpointer-view)
- **pg_stat_clear_snapshot** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_database** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_database](monitoring-stats.md#monitoring-pg-stat-database-view)
- **pg_stat_database_conflicts** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_database_conflicts](monitoring-stats.md#monitoring-pg-stat-database-conflicts-view)
- **pg_stat_file** — [Generic File Access Functions](functions-admin.md#functions-admin-genfile)
- **pg_stat_get_activity** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_activity** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_activity_start** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_client_addr** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_client_port** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_dbid** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_idset** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_io** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_lock** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_pid** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_start** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_subxact** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_userid** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_wait_event** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_wait_event_type** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_wal** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_backend_xact_start** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_snapshot_timestamp** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_xact_blocks_fetched** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_get_xact_blocks_hit** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_gssapi** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_gssapi](monitoring-stats.md#monitoring-pg-stat-gssapi-view)
- **pg_stat_io** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_io](monitoring-stats.md#monitoring-pg-stat-io-view)
- **pg_stat_kind_info** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_kind_info](monitoring-stats.md#monitoring-pg-stat-kind-info-view)
- **pg_stat_lock** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_lock](monitoring-stats.md#monitoring-pg-stat-lock-view)
- **pg_stat_progress_analyze** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [ANALYZE Progress Reporting](progress-reporting.md#analyze-progress-reporting)
- **pg_stat_progress_basebackup** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [Base Backup Progress Reporting](progress-reporting.md#basebackup-progress-reporting)
- **pg_stat_progress_cluster** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [CLUSTER Progress Reporting](progress-reporting.md#cluster-progress-reporting)
- **pg_stat_progress_copy** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [COPY Progress Reporting](progress-reporting.md#copy-progress-reporting)
- **pg_stat_progress_create_index** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [CREATE INDEX Progress Reporting](progress-reporting.md#create-index-progress-reporting)
- **pg_stat_progress_data_checksums** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [Data Checksum Progress Reporting](progress-reporting.md#data-checksum-progress-reporting)
- **pg_stat_progress_repack** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [REPACK Progress Reporting](progress-reporting.md#repack-progress-reporting)
- **pg_stat_progress_vacuum** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [VACUUM Progress Reporting](progress-reporting.md#vacuum-progress-reporting)
- **pg_stat_recovery** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_recovery](monitoring-stats.md#monitoring-pg-stat-recovery-view)
- **pg_stat_recovery_prefetch** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_recovery_prefetch](monitoring-stats.md#monitoring-pg-stat-recovery-prefetch)
- **pg_stat_replication** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_replication](monitoring-stats.md#monitoring-pg-stat-replication-view)
- **pg_stat_replication_slots** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_replication_slots](monitoring-stats.md#monitoring-pg-stat-replication-slots-view)
- **pg_stat_reset** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_reset_backend_stats** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_reset_replication_slot** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_reset_shared** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_reset_single_function_counters** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_reset_single_table_counters** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_reset_slru** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_reset_subscription_stats** — [Statistics Functions](monitoring-stats.md#monitoring-stats-functions)
- **pg_stat_slru** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_slru](monitoring-stats.md#monitoring-pg-stat-slru-view)
- **pg_stat_ssl** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_ssl](monitoring-stats.md#monitoring-pg-stat-ssl-view)
- **pg_stat_statements** — [pg_stat_statements — track statistics of SQL planning and execution](pgstatstatements.md)
  - function — [Functions](pgstatstatements.md#pgstatstatements-funcs)
- **pg_stat_statements.max configuration parameter** — [Configuration Parameters](pgstatstatements.md#pgstatstatements-config-params)
- **pg_stat_statements.save configuration parameter** — [Configuration Parameters](pgstatstatements.md#pgstatstatements-config-params)
- **pg_stat_statements.track configuration parameter** — [Configuration Parameters](pgstatstatements.md#pgstatstatements-config-params)
- **pg_stat_statements.track_planning configuration parameter** — [Configuration Parameters](pgstatstatements.md#pgstatstatements-config-params)
- **pg_stat_statements.track_utility configuration parameter** — [Configuration Parameters](pgstatstatements.md#pgstatstatements-config-params)
- **pg_stat_statements_info** — [The pg_stat_statements_info View](pgstatstatements.md#pgstatstatements-pg-stat-statements-info)
- **pg_stat_statements_reset** — [Functions](pgstatstatements.md#pgstatstatements-funcs)
- **pg_stat_subscription** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_subscription](monitoring-stats.md#monitoring-pg-stat-subscription)
- **pg_stat_subscription_stats** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_subscription_stats](monitoring-stats.md#monitoring-pg-stat-subscription-stats)
- **pg_stat_sys_indexes** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views)
- **pg_stat_sys_tables** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views)
- **pg_stat_user_functions** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_user_functions](monitoring-stats.md#monitoring-pg-stat-user-functions-view)
- **pg_stat_user_indexes** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views)
- **pg_stat_user_tables** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views)
- **pg_stat_wal** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_wal](monitoring-stats.md#monitoring-pg-stat-wal-view)
- **pg_stat_wal_receiver** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views), [pg_stat_wal_receiver](monitoring-stats.md#monitoring-pg-stat-wal-receiver-view)
- **pg_stat_xact_all_tables** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views)
- **pg_stat_xact_sys_tables** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views)
- **pg_stat_xact_user_functions** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views)
- **pg_stat_xact_user_tables** — [Viewing Statistics](monitoring-stats.md#monitoring-stats-views)
- **pg_subscription** — [pg_subscription](catalog-pg-subscription.md)
- **pg_subscription_rel** — [pg_subscription_rel](catalog-pg-subscription-rel.md)
- **pg_surgery** — [pg_surgery — perform low-level surgery on relation data](pgsurgery.md)
- **pg_switch_wal** — [Backup Control Functions](functions-admin.md#functions-admin-backup)
- **pg_sync_replication_slots** — [Replication Management Functions](functions-admin.md#functions-replication)
- **pg_tables** — [pg_tables](view-pg-tables.md)
- **pg_tablespace** — [pg_tablespace](catalog-pg-tablespace.md)
- **pg_tablespace_databases** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_tablespace_location** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_tablespace_size** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_table_is_visible** — [Schema Visibility Inquiry Functions](functions-info.md#functions-info-schema)
- **pg_table_size** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_temp** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
  - securing functions — [Writing `SECURITY DEFINER` Functions Safely](sql-createfunction.md#sql-createfunction-security)
- **pg_terminate_backend** — [Server Signaling Functions](functions-admin.md#functions-admin-signal)
- **pg_test_fsync** — [pg_test_fsync](pgtestfsync.md)
- **pg_test_timing** — [pg_test_timing](pgtesttiming.md)
- **pg_timezone_abbrevs** — [pg_timezone_abbrevs](view-pg-timezone-abbrevs.md)
- **pg_timezone_names** — [pg_timezone_names](view-pg-timezone-names.md)
- **pg_total_relation_size** — [Database Object Management Functions](functions-admin.md#functions-admin-dbobject)
- **pg_transform** — [pg_transform](catalog-pg-transform.md)
- **pg_trgm** — [pg_trgm — support for similarity of text using trigram matching](pgtrgm.md)
- **pg_trgm.similarity_threshold configuration parameter** — [GUC Parameters](pgtrgm.md#pgtrgm-guc)
- **pg_trgm.strict_word_similarity_threshold configuration parameter** — [GUC Parameters](pgtrgm.md#pgtrgm-guc)
- **pg_trgm.word_similarity_threshold configuration parameter** — [GUC Parameters](pgtrgm.md#pgtrgm-guc)
- **pg_trigger** — [pg_trigger](catalog-pg-trigger.md)
- **pg_trigger_depth** — [Session Information Functions](functions-info.md#functions-info-session)
- **pg_try_advisory_lock** — [Advisory Lock Functions](functions-admin.md#functions-advisory-locks)
- **pg_try_advisory_lock_shared** — [Advisory Lock Functions](functions-admin.md#functions-advisory-locks)
- **pg_try_advisory_xact_lock** — [Advisory Lock Functions](functions-admin.md#functions-advisory-locks)
- **pg_try_advisory_xact_lock_shared** — [Advisory Lock Functions](functions-admin.md#functions-advisory-locks)
- **pg_ts_config** — [pg_ts_config](catalog-pg-ts-config.md)
- **pg_ts_config_is_visible** — [Schema Visibility Inquiry Functions](functions-info.md#functions-info-schema)
- **pg_ts_config_map** — [pg_ts_config_map](catalog-pg-ts-config-map.md)
- **pg_ts_dict** — [pg_ts_dict](catalog-pg-ts-dict.md)
- **pg_ts_dict_is_visible** — [Schema Visibility Inquiry Functions](functions-info.md#functions-info-schema)
- **pg_ts_parser** — [pg_ts_parser](catalog-pg-ts-parser.md)
- **pg_ts_parser_is_visible** — [Schema Visibility Inquiry Functions](functions-info.md#functions-info-schema)
- **pg_ts_template** — [pg_ts_template](catalog-pg-ts-template.md)
- **pg_ts_template_is_visible** — [Schema Visibility Inquiry Functions](functions-info.md#functions-info-schema)
- **pg_type** — [pg_type](catalog-pg-type.md)
- **pg_typeof** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **pg_type_is_visible** — [Schema Visibility Inquiry Functions](functions-info.md#functions-info-schema)
- **pg_upgrade** — [pg_upgrade](pgupgrade.md)
- **pg_user** — [pg_user](view-pg-user.md)
- **pg_user_mapping** — [pg_user_mapping](catalog-pg-user-mapping.md)
- **pg_user_mappings** — [pg_user_mappings](view-pg-user-mappings.md)
- **pg_verifybackup** — [pg_verifybackup](app-pgverifybackup.md)
- **pg_views** — [pg_views](view-pg-views.md)
- **pg_visibility** — [pg_visibility — visibility map information and utilities](pgvisibility.md)
- **pg_visible_in_snapshot** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **pg_wait_events** — [pg_wait_events](view-pg-wait-events.md)
- **pg_waldump** — [pg_waldump](pgwaldump.md)
- **pg_walfile_name** — [Backup Control Functions](functions-admin.md#functions-admin-backup)
- **pg_walfile_name_offset** — [Backup Control Functions](functions-admin.md#functions-admin-backup)
- **pg_walinspect** — [pg_walinspect — low-level WAL inspection](pgwalinspect.md)
- **pg_walsummary** — [pg_walsummary](app-pgwalsummary.md)
- **pg_wal_lsn_diff** — [Backup Control Functions](functions-admin.md#functions-admin-backup)
- **pg_wal_replay_pause** — [Recovery Control Functions](functions-admin.md#functions-recovery-control)
- **pg_wal_replay_resume** — [Recovery Control Functions](functions-admin.md#functions-recovery-control)
- **pg_wal_summary_contents** — [WAL Summarization Information Functions](functions-info.md#functions-info-wal-summary)
- **pg_xact_commit_timestamp** — [Committed Transaction Information Functions](functions-info.md#functions-info-commit-timestamp)
- **pg_xact_commit_timestamp_origin** — [Committed Transaction Information Functions](functions-info.md#functions-info-commit-timestamp)
- **pg_xact_status** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **pg_xlogdump** — [`pg_xlogdump` renamed to `pg_waldump`](pgxlogdump.md) — *see* pg_waldump
- **phantom read** — [Transaction Isolation](transaction-iso.md)
- **phraseto_tsquery** — [Text Search Functions and Operators](functions-textsearch.md), [Parsing Queries](textsearch-controls.md#textsearch-parsing-queries)
- **pi** — [Mathematical Functions and Operators](functions-math.md)
- **PIC** — [Compiling and Linking Dynamically-Loaded Functions](xfunc-c.md#dfunc)
- **PID**
  - determining PID of server process
    - in libpq — [Connection Status Functions](libpq-status.md)
- **pipelining**
  - in libpq — [Pipeline Mode](libpq-pipeline-mode.md)
  - protocol specification — [Pipelining](protocol-flow.md#protocol-flow-pipelining)
- **PITR** — [Continuous Archiving and Point-in-Time Recovery (PITR)](continuous-archiving.md)
- **PITR standby** — [Log-Shipping Standby Servers](warm-standby.md)
- **pkg-config** — [Requirements](install-requirements.md)
  - with
   ecpg — [Processing Embedded SQL Programs](ecpg-process.md)
  - with
      libpq — [Building libpq Programs](libpq-build.md)
- **PL/Perl** — [PL/Perl — Perl Procedural Language](plperl.md)
- **PL/PerlU** — [Trusted and Untrusted PL/Perl](plperl-trusted.md)
- **PL/pgSQL** — [PL/pgSQL — SQL Procedural Language](plpgsql.md)
- **PL/Python** — [PL/Python — Python Procedural Language](plpython.md)
- **PL/SQL (Oracle)**
  - porting to PL/pgSQL — [Porting from Oracle PL/SQL](plpgsql-porting.md)
- **PL/Tcl** — [PL/Tcl — Tcl Procedural Language](pltcl.md)
- **plainto_tsquery** — [Text Search Functions and Operators](functions-textsearch.md), [Parsing Queries](textsearch-controls.md#textsearch-parsing-queries)
- **plan_cache_mode configuration parameter** — [Other Planner Options](runtime-config-query.md#runtime-config-query-other)
- **plperl.on_init configuration parameter** — [Configuration](plperl-under-the-hood.md#plperl-config)
- **plperl.on_plperlu_init configuration parameter** — [Configuration](plperl-under-the-hood.md#plperl-config)
- **plperl.on_plperl_init configuration parameter** — [Configuration](plperl-under-the-hood.md#plperl-config)
- **plperl.use_strict configuration parameter** — [Configuration](plperl-under-the-hood.md#plperl-config)
- **plpgsql.check_asserts configuration parameter** — [Checking Assertions](plpgsql-errors-and-messages.md#plpgsql-statements-assert)
- **plpgsql.variable_conflict configuration parameter** — [Variable Substitution](plpgsql-implementation.md#plpgsql-var-subst)
- **pltcl.start_proc configuration parameter** — [PL/Tcl Configuration](pltcl-config.md)
- **pltclu.start_proc configuration parameter** — [PL/Tcl Configuration](pltcl-config.md)
- **point** — [Points](datatype-geometric.md#datatype-geometric-points), [Geometric Functions and Operators](functions-geometry.md)
- **point-in-time recovery** — [Continuous Archiving and Point-in-Time Recovery (PITR)](continuous-archiving.md)
- **policy** — [Row Security Policies](ddl-rowsecurity.md)
- **polygon** — [Polygons](datatype-geometric.md#datatype-polygon), [Geometric Functions and Operators](functions-geometry.md)
- **polymorphic function** — [Polymorphic Types](extend-type-system.md#extend-types-polymorphic)
- **polymorphic type** — [Polymorphic Types](extend-type-system.md#extend-types-polymorphic)
- **popcount** — *see* bit_count
- **popen** — [Geometric Functions and Operators](functions-geometry.md)
- **populate_record** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **port** — [Parameter Key Words](libpq-connect.md#libpq-paramkeywords)
- **port configuration parameter** — [Connection Settings](runtime-config-connection.md#runtime-config-connection-settings)
- **portal**
  - DECLARE — [DECLARE](sql-declare.md)
  - in PL/pgSQL — [Opening Cursors](plpgsql-cursors.md#plpgsql-cursor-opening)
- **position** — [String Functions and Operators](functions-string.md), [Binary String Functions and Operators](functions-binarystring.md), [Bit String Functions and Operators](functions-bitstring.md)
- **POSITION_REGEX** — [Differences from SQL Standard and XQuery](functions-matching.md#posix-vs-xquery)
- **POSTGRES** — [The Berkeley POSTGRES Project](history.md#history-berkeley)
- **postgres** — [Architectural Fundamentals](tutorial-arch.md), [Starting the Database Server](server-start.md), [Creating a Database](manage-ag-createdb.md), [postgres](app-postgres.md)
- **postgres user** — [The PostgreSQL User Account](postgres-user.md)
- **Postgres95** — [Postgres95](history.md#history-postgres95)
- **postgresql.auto.conf** — [Parameter Interaction via the Configuration File](config-setting.md#config-setting-configuration-file)
- **postgresql.conf** — [Parameter Interaction via the Configuration File](config-setting.md#config-setting-configuration-file)
- **postgres_fdw** — [postgres_fdw — access data stored in external PostgreSQL servers](postgres-fdw.md)
- **postgres_fdw.application_name configuration parameter** — [Configuration Parameters](postgres-fdw.md#postgres-fdw-configuration-parameters)
- **post_auth_delay configuration parameter** — [Developer Options](runtime-config-developer.md)
- **power** — [Mathematical Functions and Operators](functions-math.md)
- **PQAUTHDATA_OAUTH_BEARER_TOKEN** — [Hook Types](libpq-oauth.md#libpq-oauth-authdata-hooks-types)
- **PQAUTHDATA_OAUTH_BEARER_TOKEN_V2**
  - PQAUTHDATA_OAUTH_BEARER_TOKEN — [Hook Types](libpq-oauth.md#libpq-oauth-authdata-hooks-types)
- **PQAUTHDATA_PROMPT_OAUTH_DEVICE** — [Hook Types](libpq-oauth.md#libpq-oauth-authdata-hooks-types)
- **PQbackendPID** — [Connection Status Functions](libpq-status.md)
- **PQbinaryTuples** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
  - with COPY — [Functions Associated with the `COPY` Command](libpq-copy.md)
- **PQcancel** — [Obsolete Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-deprecated)
- **PQcancelBlocking** — [Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-functions)
- **PQcancelCreate** — [Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-functions)
- **PQcancelErrorMessage** — [Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-functions)
- **PQcancelFinish** — [Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-functions)
- **PQcancelPoll** — [Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-functions)
- **PQcancelReset** — [Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-functions)
- **PQcancelSocket** — [Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-functions)
- **PQcancelStart** — [Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-functions)
- **PQcancelStatus** — [Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-functions)
- **PQchangePassword** — [Miscellaneous Functions](libpq-misc.md)
- **PQclear** — [Main Functions](libpq-exec.md#libpq-exec-main)
- **PQclientEncoding** — [Control Functions](libpq-control.md)
- **PQclosePortal** — [Main Functions](libpq-exec.md#libpq-exec-main)
- **PQclosePrepared** — [Main Functions](libpq-exec.md#libpq-exec-main)
- **PQcmdStatus** — [Retrieving Other Result Information](libpq-exec.md#libpq-exec-nonselect)
- **PQcmdTuples** — [Retrieving Other Result Information](libpq-exec.md#libpq-exec-nonselect)
- **PQconndefaults** — [Database Connection Control Functions](libpq-connect.md)
- **PQconnectdb** — [Database Connection Control Functions](libpq-connect.md)
- **PQconnectdbParams** — [Database Connection Control Functions](libpq-connect.md)
- **PQconnectionNeedsPassword** — [Connection Status Functions](libpq-status.md)
- **PQconnectionUsedGSSAPI** — [Connection Status Functions](libpq-status.md)
- **PQconnectionUsedPassword** — [Connection Status Functions](libpq-status.md)
- **PQconnectPoll** — [Database Connection Control Functions](libpq-connect.md)
- **PQconnectStart** — [Database Connection Control Functions](libpq-connect.md)
- **PQconnectStartParams** — [Database Connection Control Functions](libpq-connect.md)
- **PQconninfo** — [Database Connection Control Functions](libpq-connect.md)
- **PQconninfoFree** — [Miscellaneous Functions](libpq-misc.md)
- **PQconninfoParse** — [Database Connection Control Functions](libpq-connect.md)
- **PQconsumeInput** — [Asynchronous Command Processing](libpq-async.md)
- **PQcopyResult** — [Miscellaneous Functions](libpq-misc.md)
- **PQdb** — [Connection Status Functions](libpq-status.md)
- **PQdescribePortal** — [Main Functions](libpq-exec.md#libpq-exec-main)
- **PQdescribePrepared** — [Main Functions](libpq-exec.md#libpq-exec-main)
- **PQencryptPassword** — [Miscellaneous Functions](libpq-misc.md)
- **PQencryptPasswordConn** — [Miscellaneous Functions](libpq-misc.md)
- **PQendcopy** — [Obsolete Functions for `COPY`](libpq-copy.md#libpq-copy-deprecated)
- **PQenterPipelineMode** — [Functions Associated with Pipeline Mode](libpq-pipeline-mode.md#libpq-pipeline-functions)
- **PQerrorMessage** — [Connection Status Functions](libpq-status.md)
- **PQescapeBytea** — [Escaping Strings for Inclusion in SQL Commands](libpq-exec.md#libpq-exec-escape-string)
- **PQescapeByteaConn** — [Escaping Strings for Inclusion in SQL Commands](libpq-exec.md#libpq-exec-escape-string)
- **PQescapeIdentifier** — [Escaping Strings for Inclusion in SQL Commands](libpq-exec.md#libpq-exec-escape-string)
- **PQescapeLiteral** — [Escaping Strings for Inclusion in SQL Commands](libpq-exec.md#libpq-exec-escape-string)
- **PQescapeString** — [Escaping Strings for Inclusion in SQL Commands](libpq-exec.md#libpq-exec-escape-string)
- **PQescapeStringConn** — [Escaping Strings for Inclusion in SQL Commands](libpq-exec.md#libpq-exec-escape-string)
- **PQexec** — [Main Functions](libpq-exec.md#libpq-exec-main)
- **PQexecParams** — [Main Functions](libpq-exec.md#libpq-exec-main)
- **PQexecPrepared** — [Main Functions](libpq-exec.md#libpq-exec-main)
- **PQexitPipelineMode** — [Functions Associated with Pipeline Mode](libpq-pipeline-mode.md#libpq-pipeline-functions)
- **PQfformat** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
  - with COPY — [Functions Associated with the `COPY` Command](libpq-copy.md)
- **PQfinish** — [Database Connection Control Functions](libpq-connect.md)
- **PQfireResultCreateEvents** — [Miscellaneous Functions](libpq-misc.md)
- **PQflush** — [Asynchronous Command Processing](libpq-async.md)
- **PQfmod** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
- **PQfn** — [The Fast-Path Interface](libpq-fastpath.md)
- **PQfname** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
- **PQfnumber** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
- **PQfreeCancel** — [Obsolete Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-deprecated)
- **PQfreemem** — [Miscellaneous Functions](libpq-misc.md)
- **PQfsize** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
- **PQftable** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
- **PQftablecol** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
- **PQftype** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
- **PQfullProtocolVersion** — [Connection Status Functions](libpq-status.md)
- **PQgetAuthDataHook** — [Authdata Hooks](libpq-oauth.md#libpq-oauth-authdata-hooks)
- **PQgetCancel** — [Obsolete Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-deprecated)
- **PQgetCopyData** — [Functions for Receiving `COPY` Data](libpq-copy.md#libpq-copy-receive)
- **PQgetCurrentTimeUSec** — [Miscellaneous Functions](libpq-misc.md)
- **PQgetisnull** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
- **PQgetlength** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
- **PQgetline** — [Obsolete Functions for `COPY`](libpq-copy.md#libpq-copy-deprecated)
- **PQgetlineAsync** — [Obsolete Functions for `COPY`](libpq-copy.md#libpq-copy-deprecated)
- **PQgetResult** — [Asynchronous Command Processing](libpq-async.md)
- **PQgetssl** — [Connection Status Functions](libpq-status.md)
- **PQgetSSLKeyPassHook_OpenSSL** — [Database Connection Control Functions](libpq-connect.md)
- **PQgetvalue** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
- **PQhost** — [Connection Status Functions](libpq-status.md)
- **PQhostaddr** — [Connection Status Functions](libpq-status.md)
- **PQinitOpenSSL** — [SSL Library Initialization](libpq-ssl.md#libpq-ssl-initialize)
- **PQinitSSL** — [SSL Library Initialization](libpq-ssl.md#libpq-ssl-initialize)
- **PQinstanceData** — [Event Support Functions](libpq-events.md#libpq-events-funcs)
- **PQisBusy** — [Asynchronous Command Processing](libpq-async.md)
- **PQisnonblocking** — [Asynchronous Command Processing](libpq-async.md)
- **PQisthreadsafe** — [Behavior in Threaded Programs](libpq-threading.md)
- **PQlibVersion** — [Miscellaneous Functions](libpq-misc.md); *see also* PQserverVersion
- **PQmakeEmptyPGresult** — [Miscellaneous Functions](libpq-misc.md)
- **PQnfields** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
  - with COPY — [Functions Associated with the `COPY` Command](libpq-copy.md)
- **PQnotifies** — [Asynchronous Notification](libpq-notify.md)
- **PQnparams** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
- **PQntuples** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
- **PQoidStatus** — [Retrieving Other Result Information](libpq-exec.md#libpq-exec-nonselect)
- **PQoidValue** — [Retrieving Other Result Information](libpq-exec.md#libpq-exec-nonselect)
- **PQoptions** — [Connection Status Functions](libpq-status.md)
- **PQparameterStatus** — [Connection Status Functions](libpq-status.md)
- **PQparamtype** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
- **PQpass** — [Connection Status Functions](libpq-status.md)
- **PQping** — [Database Connection Control Functions](libpq-connect.md)
- **PQpingParams** — [Database Connection Control Functions](libpq-connect.md)
- **PQpipelineStatus** — [Functions Associated with Pipeline Mode](libpq-pipeline-mode.md#libpq-pipeline-functions)
- **PQpipelineSync** — [Functions Associated with Pipeline Mode](libpq-pipeline-mode.md#libpq-pipeline-functions)
- **PQport** — [Connection Status Functions](libpq-status.md)
- **PQprepare** — [Main Functions](libpq-exec.md#libpq-exec-main)
- **PQprint** — [Retrieving Query Result Information](libpq-exec.md#libpq-exec-select-info)
- **PQprotocolVersion** — [Connection Status Functions](libpq-status.md)
- **PQputCopyData** — [Functions for Sending `COPY` Data](libpq-copy.md#libpq-copy-send)
- **PQputCopyEnd** — [Functions for Sending `COPY` Data](libpq-copy.md#libpq-copy-send)
- **PQputline** — [Obsolete Functions for `COPY`](libpq-copy.md#libpq-copy-deprecated)
- **PQputnbytes** — [Obsolete Functions for `COPY`](libpq-copy.md#libpq-copy-deprecated)
- **PQregisterEventProc** — [Event Support Functions](libpq-events.md#libpq-events-funcs)
- **PQrequestCancel** — [Obsolete Functions for Sending Cancel Requests](libpq-cancel.md#libpq-cancel-deprecated)
- **PQreset** — [Database Connection Control Functions](libpq-connect.md)
- **PQresetPoll** — [Database Connection Control Functions](libpq-connect.md)
- **PQresetStart** — [Database Connection Control Functions](libpq-connect.md)
- **PQresStatus** — [Main Functions](libpq-exec.md#libpq-exec-main)
- **PQresultAlloc** — [Miscellaneous Functions](libpq-misc.md)
- **PQresultErrorField** — [Main Functions](libpq-exec.md#libpq-exec-main)
- **PQresultErrorMessage** — [Main Functions](libpq-exec.md#libpq-exec-main)
- **PQresultInstanceData** — [Event Support Functions](libpq-events.md#libpq-events-funcs)
- **PQresultMemorySize** — [Miscellaneous Functions](libpq-misc.md)
- **PQresultSetInstanceData** — [Event Support Functions](libpq-events.md#libpq-events-funcs)
- **PQresultStatus** — [Main Functions](libpq-exec.md#libpq-exec-main)
- **PQresultVerboseErrorMessage** — [Main Functions](libpq-exec.md#libpq-exec-main)
- **PQsendClosePortal** — [Asynchronous Command Processing](libpq-async.md)
- **PQsendClosePrepared** — [Asynchronous Command Processing](libpq-async.md)
- **PQsendDescribePortal** — [Asynchronous Command Processing](libpq-async.md)
- **PQsendDescribePrepared** — [Asynchronous Command Processing](libpq-async.md)
- **PQsendFlushRequest** — [Functions Associated with Pipeline Mode](libpq-pipeline-mode.md#libpq-pipeline-functions)
- **PQsendPipelineSync** — [Functions Associated with Pipeline Mode](libpq-pipeline-mode.md#libpq-pipeline-functions)
- **PQsendPrepare** — [Asynchronous Command Processing](libpq-async.md)
- **PQsendQuery** — [Asynchronous Command Processing](libpq-async.md)
- **PQsendQueryParams** — [Asynchronous Command Processing](libpq-async.md)
- **PQsendQueryPrepared** — [Asynchronous Command Processing](libpq-async.md)
- **PQserverVersion** — [Connection Status Functions](libpq-status.md)
- **PQsetAuthDataHook** — [Authdata Hooks](libpq-oauth.md#libpq-oauth-authdata-hooks)
- **PQsetChunkedRowsMode** — [Retrieving Query Results in Chunks](libpq-single-row-mode.md)
- **PQsetClientEncoding** — [Control Functions](libpq-control.md)
- **PQsetdb** — [Database Connection Control Functions](libpq-connect.md)
- **PQsetdbLogin** — [Database Connection Control Functions](libpq-connect.md)
- **PQsetErrorContextVisibility** — [Control Functions](libpq-control.md)
- **PQsetErrorVerbosity** — [Control Functions](libpq-control.md)
- **PQsetInstanceData** — [Event Support Functions](libpq-events.md#libpq-events-funcs)
- **PQsetnonblocking** — [Asynchronous Command Processing](libpq-async.md)
- **PQsetNoticeProcessor** — [Notice Processing](libpq-notice-processing.md)
- **PQsetNoticeReceiver** — [Notice Processing](libpq-notice-processing.md)
- **PQsetResultAttrs** — [Miscellaneous Functions](libpq-misc.md)
- **PQsetSingleRowMode** — [Retrieving Query Results in Chunks](libpq-single-row-mode.md)
- **PQsetSSLKeyPassHook_OpenSSL** — [Database Connection Control Functions](libpq-connect.md)
- **PQsetTraceFlags** — [Control Functions](libpq-control.md)
- **PQsetvalue** — [Miscellaneous Functions](libpq-misc.md)
- **PQsocket** — [Connection Status Functions](libpq-status.md)
- **PQsocketPoll** — [Database Connection Control Functions](libpq-connect.md)
- **PQsslAttribute** — [Connection Status Functions](libpq-status.md)
- **PQsslAttributeNames** — [Connection Status Functions](libpq-status.md)
- **PQsslInUse** — [Connection Status Functions](libpq-status.md)
- **PQsslStruct** — [Connection Status Functions](libpq-status.md)
- **PQstatus** — [Connection Status Functions](libpq-status.md)
- **PQtrace** — [Control Functions](libpq-control.md)
- **PQtransactionStatus** — [Connection Status Functions](libpq-status.md)
- **PQtty** — [Connection Status Functions](libpq-status.md)
- **PQunescapeBytea** — [Escaping Strings for Inclusion in SQL Commands](libpq-exec.md#libpq-exec-escape-string)
- **PQuntrace** — [Control Functions](libpq-control.md)
- **PQuser** — [Connection Status Functions](libpq-status.md)
- **predicate locking** — [Serializable Isolation Level](transaction-iso.md#xact-serializable)
- **PREPARE** — [PREPARE](sql-prepare.md)
- **PREPARE TRANSACTION** — [PREPARE TRANSACTION](sql-prepare-transaction.md)
- **prepared statements**
  - creating — [PREPARE](sql-prepare.md)
  - executing — [EXECUTE](sql-execute.md)
  - removing — [DEALLOCATE](sql-deallocate.md)
  - showing the query plan — [EXPLAIN](sql-explain.md)
- **preparing a query**
  - in PL/pgSQL — [Plan Caching](plpgsql-implementation.md#plpgsql-plan-caching)
  - in PL/Python — [Database Access Functions](plpython-database.md#plpython-database-access-funcs)
  - in PL/Tcl — [Database Access from PL/Tcl](pltcl-dbaccess.md)
- **pre_auth_delay configuration parameter** — [Developer Options](runtime-config-developer.md)
- **primary key** — [Primary Keys](ddl-constraints.md#ddl-constraints-primary-keys)
- **primary_conninfo configuration parameter** — [Standby Servers](runtime-config-replication.md#runtime-config-replication-standby)
- **primary_slot_name configuration parameter** — [Standby Servers](runtime-config-replication.md#runtime-config-replication-standby)
- **privilege** — [Privileges](ddl-priv.md)
  - default — [Privileges](ddl-priv.md)
  - querying — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
  - with rules — [Rules and Privileges](rules-privileges.md)
  - for schemas — [Schemas and Privileges](ddl-schemas.md#ddl-schemas-priv)
  - with views — [Rules and Privileges](rules-privileges.md)
- **procedural language** — [Procedural Languages](xplang.md)
  - externally maintained — [Procedural Languages](external-pl.md)
  - handler for — [Writing a Procedural Language Handler](plhandler.md)
- **procedure**
  - user-defined — [User-Defined Procedures](xproc.md)
- **procedures**
  - output parameter — [SQL Procedures with Output Parameters](xfunc-sql.md#xfunc-output-parameters-proc)
- **property graph** — [Property Graphs](ddl-property-graphs.md)
- **protocol**
  - frontend-backend — [Frontend/Backend Protocol](protocol.md)
- **ps**
  - to monitor activity — [Standard Unix Tools](monitoring-ps.md)
- **psql** — [Accessing a Database](tutorial-accessdb.md), [psql](app-psql.md)
- **Python** — [PL/Python — Python Procedural Language](plpython.md)

## Q

- **qualified name** — [Creating a Schema](ddl-schemas.md#ddl-schemas-create)
- **query** — [Querying a Table](tutorial-select.md), [Queries](queries.md)
- **query cancellation** — [Canceling Queries in Progress](libpq-cancel.md)
- **query plan** — [Using `EXPLAIN`](using-explain.md)
- **query tree** — [The Query Tree](querytree.md)
- **querytree** — [Text Search Functions and Operators](functions-textsearch.md), [Manipulating Queries](textsearch-features.md#textsearch-manipulate-tsquery)
- **quotation marks**
  - and identifiers — [Identifiers and Key Words](sql-syntax-lexical.md#sql-syntax-identifiers)
  - escaping — [String Constants](sql-syntax-lexical.md#sql-syntax-strings)
- **quote_all_identifiers configuration parameter** — [Previous PostgreSQL Versions](runtime-config-compatible.md#runtime-config-compatible-version)
- **quote_ident** — [String Functions and Operators](functions-string.md)
  - in PL/Perl — [Utility Functions in PL/Perl](plperl-builtins.md#plperl-utility-functions)
  - use in PL/pgSQL — [Executing Dynamic Commands](plpgsql-statements.md#plpgsql-statements-executing-dyn)
- **quote_literal** — [String Functions and Operators](functions-string.md)
  - in PL/Perl — [Utility Functions in PL/Perl](plperl-builtins.md#plperl-utility-functions)
  - use in PL/pgSQL — [Executing Dynamic Commands](plpgsql-statements.md#plpgsql-statements-executing-dyn)
- **quote_nullable** — [String Functions and Operators](functions-string.md)
  - in PL/Perl — [Utility Functions in PL/Perl](plperl-builtins.md#plperl-utility-functions)
  - use in PL/pgSQL — [Executing Dynamic Commands](plpgsql-statements.md#plpgsql-statements-executing-dyn)

## R

- **radians** — [Mathematical Functions and Operators](functions-math.md)
- **radius** — [Geometric Functions and Operators](functions-geometry.md)
- **RADIUS** — [RADIUS Authentication Removed](auth-radius.md)
- **RAISE**
  - in PL/pgSQL — [Reporting Errors and Messages](plpgsql-errors-and-messages.md#plpgsql-statements-raise)
- **random** — [Mathematical Functions and Operators](functions-math.md), [Mathematical Functions and Operators](functions-math.md), [Date/Time Functions and Operators](functions-datetime.md)
- **random_normal** — [Mathematical Functions and Operators](functions-math.md)
- **random_page_cost configuration parameter** — [Planner Cost Constants](runtime-config-query.md#runtime-config-query-constants)
- **range table** — [The Query Tree](querytree.md)
- **range type** — [Range Types](rangetypes.md)
  - exclude — [Constraints on Ranges](rangetypes.md#rangetypes-constraint)
  - indexes on — [Indexing](rangetypes.md#rangetypes-indexing)
- **range_agg** — [Aggregate Functions](functions-aggregate.md)
- **range_intersect_agg** — [Aggregate Functions](functions-aggregate.md)
- **range_merge** — [Range/Multirange Functions and Operators](functions-range.md), [Range/Multirange Functions and Operators](functions-range.md)
- **range_minus_multi** — [Range/Multirange Functions and Operators](functions-range.md)
- **rank** — [Window Functions](functions-window.md)
  - hypothetical — [Aggregate Functions](functions-aggregate.md)
- **RDTSC** — [Timing](runtime-config-resource.md#runtime-config-resource-time)
- **read committed** — [Read Committed Isolation Level](transaction-iso.md#xact-read-committed)
- **read-only transaction** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
  - setting — [SET TRANSACTION](sql-set-transaction.md)
  - setting default — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **readline** — [Requirements](install-requirements.md)
- **Readline**
  - in psql — [Command-Line Editing](app-psql.md#app-psql-readline)
- **READ_REPLICATION_SLOT** — [Streaming Replication Protocol](protocol-replication.md)
- **real** — [Floating-Point Types](datatype-numeric.md#datatype-float)
- **REASSIGN OWNED** — [REASSIGN OWNED](sql-reassign-owned.md)
- **record** — [Pseudo-Types](datatype-pseudo.md)
- **recovery.conf** — [`recovery.conf` file merged into `postgresql.conf`](recovery-config.md), [`recovery.conf` file merged into `postgresql.conf`](recovery-config.md)
- **recovery.signal** — [Archive Recovery](runtime-config-wal.md#runtime-config-wal-archive-recovery)
- **recovery_end_command configuration parameter** — [Archive Recovery](runtime-config-wal.md#runtime-config-wal-archive-recovery)
- **recovery_init_sync_method configuration parameter** — [Error Handling](runtime-config-error-handling.md)
- **recovery_min_apply_delay configuration parameter** — [Standby Servers](runtime-config-replication.md#runtime-config-replication-standby)
- **recovery_prefetch configuration parameter** — [Recovery](runtime-config-wal.md#runtime-config-wal-recovery)
- **recovery_target configuration parameter** — [Recovery Target](runtime-config-wal.md#runtime-config-wal-recovery-target)
- **recovery_target_action configuration parameter** — [Recovery Target](runtime-config-wal.md#runtime-config-wal-recovery-target)
- **recovery_target_inclusive configuration parameter** — [Recovery Target](runtime-config-wal.md#runtime-config-wal-recovery-target)
- **recovery_target_lsn configuration parameter** — [Recovery Target](runtime-config-wal.md#runtime-config-wal-recovery-target)
- **recovery_target_name configuration parameter** — [Recovery Target](runtime-config-wal.md#runtime-config-wal-recovery-target)
- **recovery_target_time configuration parameter** — [Recovery Target](runtime-config-wal.md#runtime-config-wal-recovery-target)
- **recovery_target_timeline configuration parameter** — [Recovery Target](runtime-config-wal.md#runtime-config-wal-recovery-target)
- **recovery_target_xid configuration parameter** — [Recovery Target](runtime-config-wal.md#runtime-config-wal-recovery-target)
- **rectangle** — [Boxes](datatype-geometric.md#datatype-geometric-boxes)
- **RECURSIVE**
  - in common table expressions — [Recursive Queries](queries-with.md#queries-with-recursive)
  - in views — [Parameters](sql-createview.md#id-1.9.3.99.6)
- **recursive_worktable_factor configuration parameter** — [Other Planner Options](runtime-config-query.md#runtime-config-query-other)
- **referential integrity** — [Foreign Keys](tutorial-fk.md), [Foreign Keys](ddl-constraints.md#ddl-constraints-fk)
- **refint** — [refint Extension Removed](contrib-spi-refint.md)
- **REFRESH MATERIALIZED VIEW** — [REFRESH MATERIALIZED VIEW](sql-refreshmaterializedview.md)
- **regclass** — [Object Identifier Types](datatype-oid.md)
- **regcollation** — [Object Identifier Types](datatype-oid.md)
- **regconfig** — [Object Identifier Types](datatype-oid.md)
- **regdatabase** — [Object Identifier Types](datatype-oid.md)
- **regdictionary** — [Object Identifier Types](datatype-oid.md)
- **regexp_count** — [String Functions and Operators](functions-string.md), [`regexp_count`](functions-matching.md#functions-posix-regexp-count)
- **regexp_instr** — [String Functions and Operators](functions-string.md), [`regexp_instr`](functions-matching.md#functions-posix-regexp-instr)
- **regexp_like** — [String Functions and Operators](functions-string.md), [`regexp_like`](functions-matching.md#functions-posix-regexp-like)
- **regexp_match** — [String Functions and Operators](functions-string.md), [`regexp_match`](functions-matching.md#functions-posix-regexp-match)
- **regexp_matches** — [String Functions and Operators](functions-string.md), [`regexp_matches`](functions-matching.md#functions-posix-regexp-matches)
- **regexp_replace** — [String Functions and Operators](functions-string.md), [`regexp_replace`](functions-matching.md#functions-posix-regexp-replace)
- **regexp_split_to_array** — [String Functions and Operators](functions-string.md), [`regexp_split_to_array`](functions-matching.md#functions-posix-regexp-split-to-array)
- **regexp_split_to_table** — [String Functions and Operators](functions-string.md), [`regexp_split_to_table`](functions-matching.md#functions-posix-regexp-split-to-table)
- **regexp_substr** — [String Functions and Operators](functions-string.md), [`regexp_substr`](functions-matching.md#functions-posix-regexp-substr)
- **regnamespace** — [Object Identifier Types](datatype-oid.md)
- **regoper** — [Object Identifier Types](datatype-oid.md)
- **regoperator** — [Object Identifier Types](datatype-oid.md)
- **regproc** — [Object Identifier Types](datatype-oid.md)
- **regprocedure** — [Object Identifier Types](datatype-oid.md)
- **regression intercept** — [Aggregate Functions](functions-aggregate.md)
- **regression slope** — [Aggregate Functions](functions-aggregate.md)
- **regression test** — [Installation Procedure](install-make.md#install-procedure-make), [Installation Procedure](install-meson.md#install-procedure-meson)
- **regression tests** — [Regression Tests](regress.md)
- **regrole** — [Object Identifier Types](datatype-oid.md)
- **regr_avgx** — [Aggregate Functions](functions-aggregate.md)
- **regr_avgy** — [Aggregate Functions](functions-aggregate.md)
- **regr_count** — [Aggregate Functions](functions-aggregate.md)
- **regr_intercept** — [Aggregate Functions](functions-aggregate.md)
- **regr_r2** — [Aggregate Functions](functions-aggregate.md)
- **regr_slope** — [Aggregate Functions](functions-aggregate.md)
- **regr_sxx** — [Aggregate Functions](functions-aggregate.md)
- **regr_sxy** — [Aggregate Functions](functions-aggregate.md)
- **regr_syy** — [Aggregate Functions](functions-aggregate.md)
- **regtype** — [Object Identifier Types](datatype-oid.md)
- **regular expression** — [`SIMILAR TO` Regular Expressions](functions-matching.md#functions-similarto-regexp), [POSIX Regular Expressions](functions-matching.md#functions-posix-regexp); *see also* pattern matching
- **regular expressions**
  - and locales — [Behavior](locale.md#locale-behavior)
- **reindex** — [Routine Reindexing](routine-reindex.md)
- **REINDEX** — [REINDEX](sql-reindex.md)
- **reindexdb** — [reindexdb](app-reindexdb.md)
- **relation** — [Concepts](tutorial-concepts.md)
- **relational database** — [Concepts](tutorial-concepts.md)
- **RELEASE SAVEPOINT** — [RELEASE SAVEPOINT](sql-release-savepoint.md)
- **remove_temp_files_after_crash configuration parameter** — [Developer Options](runtime-config-developer.md)
- **REPACK** — [REPACK](sql-repack.md)
- **repeat** — [String Functions and Operators](functions-string.md)
- **repeatable read** — [Repeatable Read Isolation Level](transaction-iso.md#xact-repeatable-read)
- **replace** — [String Functions and Operators](functions-string.md)
- **replication** — [High Availability, Load Balancing, and Replication](high-availability.md)
- **Replication Origins** — [Replication Progress Tracking](replication-origins.md)
- **Replication Progress Tracking** — [Replication Progress Tracking](replication-origins.md)
- **replication slot**
  - logical replication — [Replication Slots](logicaldecoding-explanation.md#logicaldecoding-replication-slots)
  - streaming replication — [Replication Slots](warm-standby.md#streaming-replication-slots)
- **reporting errors**
  - in PL/pgSQL — [Reporting Errors and Messages](plpgsql-errors-and-messages.md#plpgsql-statements-raise)
- **reserved_connections configuration parameter** — [Connection Settings](runtime-config-connection.md#runtime-config-connection-settings)
- **RESET** — [RESET](sql-reset.md)
- **restartpoint** — [WAL Configuration](wal-configuration.md)
- **restart_after_crash configuration parameter** — [Error Handling](runtime-config-error-handling.md)
- **restore_command configuration parameter** — [Archive Recovery](runtime-config-wal.md#runtime-config-wal-archive-recovery)
- **RESTRICT**
  - with DROP — [Dependency Tracking](ddl-depend.md)
  - foreign key action — [Foreign Keys](ddl-constraints.md#ddl-constraints-fk)
- **restrict_nonsystem_relation_kind**
  - configuration parameter — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **retryable error** — [Serialization Failure Handling](mvcc-serialization-failure-handling.md)
- **RETURN NEXT**
  - in PL/pgSQL — [`RETURN NEXT` and `RETURN QUERY`](plpgsql-control-structures.md#plpgsql-statements-returning-return-next)
- **RETURN QUERY**
  - in PL/pgSQL — [`RETURN NEXT` and `RETURN QUERY`](plpgsql-control-structures.md#plpgsql-statements-returning-return-next)
- **RETURNING** — [Returning Data from Modified Rows](dml-returning.md)
- **RETURNING INTO**
  - in PL/pgSQL — [Executing a Command with a Single-Row Result](plpgsql-statements.md#plpgsql-statements-sql-onerow)
- **reverse** — [String Functions and Operators](functions-string.md), [Binary String Functions and Operators](functions-binarystring.md)
- **REVOKE** — [Privileges](ddl-priv.md), [REVOKE](sql-revoke.md)
- **right** — [String Functions and Operators](functions-string.md)
- **right join** — [Joined Tables](queries-table-expressions.md#queries-join)
- **role** — [Database Roles](database-roles.md), [Predefined Roles](predefined-roles.md)
  - applicable — [`applicable_roles`](infoschema-applicable-roles.md)
  - enabled — [`enabled_roles`](infoschema-enabled-roles.md)
  - membership in — [Role Membership](role-membership.md)
  - privilege to bypass — [Role Attributes](role-attributes.md)
  - privilege to create — [Role Attributes](role-attributes.md)
  - privilege to inherit — [Role Attributes](role-attributes.md)
  - privilege to initiate replication — [Role Attributes](role-attributes.md)
  - privilege to limit connection — [Role Attributes](role-attributes.md)
- **ROLLBACK** — [ROLLBACK](sql-rollback.md)
- **rollback**
  - psql — [Variables](app-psql.md#app-psql-variables)
- **ROLLBACK PREPARED** — [ROLLBACK PREPARED](sql-rollback-prepared.md)
- **ROLLBACK TO SAVEPOINT** — [ROLLBACK TO SAVEPOINT](sql-rollback-to.md)
- **ROLLUP** — [`GROUPING SETS`, `CUBE`, and `ROLLUP`](queries-table-expressions.md#queries-grouping-sets)
- **round** — [Mathematical Functions and Operators](functions-math.md)
- **routine** — [User-Defined Procedures](xproc.md)
- **routine maintenance** — [Routine Database Maintenance Tasks](maintenance.md)
- **row** — [Concepts](tutorial-concepts.md), [Table Basics](ddl-basics.md)
- **ROW** — [Row Constructors](sql-expressions.md#sql-syntax-row-constructors)
- **row estimation**
  - multivariate — [Multivariate Statistics Examples](multivariate-statistics-examples.md)
  - planner — [Row Estimation Examples](row-estimation-examples.md)
- **row type** — [Composite Types](rowtypes.md)
  - constructor — [Row Constructors](sql-expressions.md#sql-syntax-row-constructors)
- **row-level security** — [Row Security Policies](ddl-rowsecurity.md)
- **row-wise comparison** — [Row and Array Comparisons](functions-comparisons.md)
- **row_number** — [Window Functions](functions-window.md)
- **row_security configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **row_security_active** — [Access Privilege Inquiry Functions](functions-info.md#functions-info-access)
- **row_to_json** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **rpad** — [String Functions and Operators](functions-string.md)
- **rtrim** — [String Functions and Operators](functions-string.md), [Binary String Functions and Operators](functions-binarystring.md)
- **rule** — [The Rule System](rules.md)
  - and materialized views — [Materialized Views](rules-materializedviews.md)
  - and views — [Views and the Rule System](rules-views.md)
  - for DELETE — [Rules on `INSERT`, `UPDATE`, and `DELETE`](rules-update.md)
  - for INSERT — [Rules on `INSERT`, `UPDATE`, and `DELETE`](rules-update.md)
  - for SELECT — [How `SELECT` Rules Work](rules-views.md#rules-select)
  - compared with triggers — [Rules Versus Triggers](rules-triggers.md)
  - for UPDATE — [Rules on `INSERT`, `UPDATE`, and `DELETE`](rules-update.md)

## S

- **SAVEPOINT** — [SAVEPOINT](sql-savepoint.md)
- **savepoints**
  - defining — [SAVEPOINT](sql-savepoint.md)
  - releasing — [RELEASE SAVEPOINT](sql-release-savepoint.md)
  - rolling back — [ROLLBACK TO SAVEPOINT](sql-rollback-to.md)
- **scalar** — *see* expression
- **scale** — [Mathematical Functions and Operators](functions-math.md)
- **schema** — [Schemas](ddl-schemas.md), [Overview](manage-ag-overview.md)
  - creating — [Creating a Schema](ddl-schemas.md#ddl-schemas-create)
  - current — [The Schema Search Path](ddl-schemas.md#ddl-schemas-path), [Session Information Functions](functions-info.md#functions-info-session)
  - public — [The Public Schema](ddl-schemas.md#ddl-schemas-public)
  - removing — [Creating a Schema](ddl-schemas.md#ddl-schemas-create)
- **SCRAM** — [Password Authentication](auth-password.md)
- **scram_iterations configuration parameter** — [Authentication](runtime-config-connection.md#runtime-config-connection-authentication)
- **search path** — [The Schema Search Path](ddl-schemas.md#ddl-schemas-path)
  - current — [Session Information Functions](functions-info.md#functions-info-session)
  - object visibility — [Schema Visibility Inquiry Functions](functions-info.md#functions-info-schema)
- **search_path configuration parameter** — [The Schema Search Path](ddl-schemas.md#ddl-schemas-path), [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
  - use in securing functions — [Writing `SECURITY DEFINER` Functions Safely](sql-createfunction.md#sql-createfunction-security)
- **SECURITY LABEL** — [SECURITY LABEL](sql-security-label.md)
- **sec_to_gc** — [Cube-Based Earth Distances](earthdistance.md#earthdistance-cube-based)
- **seg** — [seg — a datatype for line segments or floating point intervals](seg.md)
- **segment_size configuration parameter** — [Preset Options](runtime-config-preset.md)
- **SELECT** — [Querying a Table](tutorial-select.md), [Queries](queries.md), [SELECT](sql-select.md)
  - determination of result type — [`SELECT` Output Columns](typeconv-select.md)
  - select list — [Select Lists](queries-select-lists.md)
- **SELECT INTO** — [SELECT INTO](sql-selectinto.md)
  - in PL/pgSQL — [Executing a Command with a Single-Row Result](plpgsql-statements.md#plpgsql-statements-sql-onerow)
- **semaphores** — [Shared Memory and Semaphores](kernel-resources.md#sysvipc)
- **send_abort_for_crash configuration parameter** — [Developer Options](runtime-config-developer.md)
- **send_abort_for_kill configuration parameter** — [Developer Options](runtime-config-developer.md)
- **sepgsql** — [sepgsql — SELinux-, label-based mandatory access control (MAC) security module](sepgsql.md)
- **sepgsql.debug_audit configuration parameter** — [GUC Parameters](sepgsql.md#sepgsql-parameters)
- **sepgsql.permissive configuration parameter** — [GUC Parameters](sepgsql.md#sepgsql-parameters)
- **sequence** — [Sequence Manipulation Functions](functions-sequence.md)
  - and serial type — [Serial Types](datatype-numeric.md#datatype-serial)
- **sequential scan** — [Planner Method Configuration](runtime-config-query.md#runtime-config-query-enable)
- **seq_page_cost configuration parameter** — [Planner Cost Constants](runtime-config-query.md#runtime-config-query-constants)
- **serial** — [Serial Types](datatype-numeric.md#datatype-serial)
- **serial2** — [Serial Types](datatype-numeric.md#datatype-serial)
- **serial4** — [Serial Types](datatype-numeric.md#datatype-serial)
- **serial8** — [Serial Types](datatype-numeric.md#datatype-serial)
- **serializable** — [Serializable Isolation Level](transaction-iso.md#xact-serializable)
- **Serializable Snapshot Isolation** — [Introduction](mvcc-intro.md)
- **serializable_buffers configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **serialization anomaly** — [Transaction Isolation](transaction-iso.md), [Serializable Isolation Level](transaction-iso.md#xact-serializable)
- **serialization failure** — [Serialization Failure Handling](mvcc-serialization-failure-handling.md)
- **server log** — [Error Reporting and Logging](runtime-config-logging.md)
  - log file maintenance — [Log File Maintenance](logfile-maintenance.md)
- **Server Name Indication** — [Parameter Key Words](libpq-connect.md#libpq-paramkeywords)
- **server spoofing** — [Preventing Server Spoofing](preventing-server-spoofing.md)
- **server_encoding configuration parameter** — [Preset Options](runtime-config-preset.md)
- **server_version configuration parameter** — [Preset Options](runtime-config-preset.md)
- **server_version_num configuration parameter** — [Preset Options](runtime-config-preset.md)
- **session_preload_libraries configuration parameter** — [Shared Library Preloading](runtime-config-client.md#runtime-config-client-preload)
- **session_replication_role configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **session_user** — [Session Information Functions](functions-info.md#functions-info-session)
- **SET** — [Configuration Settings Functions](functions-admin.md#functions-admin-set), [SET](sql-set.md)
- **SET CONSTRAINTS** — [SET CONSTRAINTS](sql-set-constraints.md)
- **set difference** — [Combining Queries (`UNION`, `INTERSECT`, `EXCEPT`)](queries-union.md)
- **set intersection** — [Combining Queries (`UNION`, `INTERSECT`, `EXCEPT`)](queries-union.md)
- **set operation** — [Combining Queries (`UNION`, `INTERSECT`, `EXCEPT`)](queries-union.md)
- **set returning functions**
  - functions — [Set Returning Functions](functions-srf.md)
- **SET ROLE** — [SET ROLE](sql-set-role.md)
- **SET SESSION AUTHORIZATION** — [SET SESSION AUTHORIZATION](sql-set-session-authorization.md)
- **SET TRANSACTION** — [SET TRANSACTION](sql-set-transaction.md)
- **set union** — [Combining Queries (`UNION`, `INTERSECT`, `EXCEPT`)](queries-union.md)
- **SET XML OPTION** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **setseed** — [Mathematical Functions and Operators](functions-math.md)
- **setval** — [Sequence Manipulation Functions](functions-sequence.md)
- **setweight** — [Text Search Functions and Operators](functions-textsearch.md), [Manipulating Documents](textsearch-features.md#textsearch-manipulate-tsvector)
  - setweight for specific lexeme(s) — [Text Search Functions and Operators](functions-textsearch.md)
- **set_bit** — [Binary String Functions and Operators](functions-binarystring.md), [Bit String Functions and Operators](functions-bitstring.md)
- **set_byte** — [Binary String Functions and Operators](functions-binarystring.md)
- **set_config** — [Configuration Settings Functions](functions-admin.md#functions-admin-set)
- **set_limit** — [Functions and Operators](pgtrgm.md#pgtrgm-funcs-ops)
- **set_masklen** — [Network Address Functions and Operators](functions-net.md)
- **sha224** — [Binary String Functions and Operators](functions-binarystring.md)
- **sha256** — [Binary String Functions and Operators](functions-binarystring.md)
- **sha384** — [Binary String Functions and Operators](functions-binarystring.md)
- **sha512** — [Binary String Functions and Operators](functions-binarystring.md)
- **shared library** — [Shared Libraries](install-post.md#install-post-shlibs), [Compiling and Linking Dynamically-Loaded Functions](xfunc-c.md#dfunc)
- **shared memory** — [Shared Memory and Semaphores](kernel-resources.md#sysvipc)
- **shared_buffers configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **shared_memory_size configuration parameter** — [Preset Options](runtime-config-preset.md)
- **shared_memory_size_in_huge_pages configuration parameter** — [Preset Options](runtime-config-preset.md)
- **shared_memory_type configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **shared_preload_libraries** — [Requesting Shared Memory at Startup](xfunc-c.md#xfunc-shared-addin-at-startup), [Requesting Shared Memory after Startup with `ShmemRequestStruct`](xfunc-c.md#xfunc-shared-addin-after-startup), [Requesting LWLocks at Startup](xfunc-c.md#xfunc-addin-lwlocks-at-startup)
- **shared_preload_libraries configuration parameter** — [Shared Library Preloading](runtime-config-client.md#runtime-config-client-preload)
- **shobj_description** — [Comment Information Functions](functions-info.md#functions-info-comment)
- **SHOW** — [Configuration Settings Functions](functions-admin.md#functions-admin-set), [SHOW](sql-show.md), [Streaming Replication Protocol](protocol-replication.md)
- **show_limit** — [Functions and Operators](pgtrgm.md#pgtrgm-funcs-ops)
- **show_trgm** — [Functions and Operators](pgtrgm.md#pgtrgm-funcs-ops)
- **shutdown** — [Shutting Down the Server](server-shutdown.md)
- **SIGHUP** — [Parameter Interaction via the Configuration File](config-setting.md#config-setting-configuration-file), [The `pg_hba.conf` File](auth-pg-hba-conf.md), [User Name Maps](auth-username-maps.md)
- **SIGINT** — [Shutting Down the Server](server-shutdown.md)
- **sign** — [Mathematical Functions and Operators](functions-math.md)
- **signal**
  - backend processes — [Server Signaling Functions](functions-admin.md#functions-admin-signal)
- **significant digits** — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)
- **SIGQUIT** — [Shutting Down the Server](server-shutdown.md)
- **SIGTERM** — [Shutting Down the Server](server-shutdown.md)
- **SIMILAR TO** — [`SIMILAR TO` Regular Expressions](functions-matching.md#functions-similarto-regexp)
- **similarity** — [Functions and Operators](pgtrgm.md#pgtrgm-funcs-ops)
- **sin** — [Mathematical Functions and Operators](functions-math.md)
- **sind** — [Mathematical Functions and Operators](functions-math.md)
- **single-user mode** — [Options for Single-User Mode](app-postgres.md#id-1.9.5.16.6.5)
- **sinh** — [Mathematical Functions and Operators](functions-math.md)
- **skeys** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **sleep** — [Delaying Execution](functions-datetime.md#functions-datetime-delay)
- **slice** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **sliced bread** — *see* TOAST
- **slope** — [Geometric Functions and Operators](functions-geometry.md)
- **SLRU** — [pg_stat_slru](monitoring-stats.md#monitoring-pg-stat-slru-view)
- **smallint** — [Integer Types](datatype-numeric.md#datatype-int)
- **smallserial** — [Serial Types](datatype-numeric.md#datatype-serial)
- **Solaris**
  - installation on — [Solaris](installation-platform-notes.md#installation-notes-solaris)
  - shared library — [Compiling and Linking Dynamically-Loaded Functions](xfunc-c.md#dfunc)
  - start script — [Starting the Database Server](server-start.md)
- **SOME** — [Aggregate Functions](functions-aggregate.md), [Subquery Expressions](functions-subquery.md), [Row and Array Comparisons](functions-comparisons.md)
- **sort** — [`intarray` Functions and Operators](intarray.md#intarray-funcs-ops)
- **sorting** — [Sorting Rows (`ORDER BY`)](queries-order.md)
- **sort_asc** — [`intarray` Functions and Operators](intarray.md#intarray-funcs-ops)
- **sort_desc** — [`intarray` Functions and Operators](intarray.md#intarray-funcs-ops)
- **soundex** — [Soundex](fuzzystrmatch.md#fuzzystrmatch-soundex)
- **SP-GiST** — *see* index
- **SPI** — [Server Programming Interface](spi.md)
  - examples — [spi — Server Programming Interface features/examples](contrib-spi.md)
- **spi_commit**
  - in PL/Perl — [Database Access from PL/Perl](plperl-builtins.md#plperl-database)
- **SPI_commit** — [SPI_commit](spi-spi-commit.md)
- **SPI_commit_and_chain** — [SPI_commit](spi-spi-commit.md)
- **SPI_connect** — [SPI_connect](spi-spi-connect.md)
- **SPI_connect_ext** — [SPI_connect](spi-spi-connect.md)
- **SPI_copytuple** — [SPI_copytuple](spi-spi-copytuple.md)
- **spi_cursor_close**
  - in PL/Perl — [Database Access from PL/Perl](plperl-builtins.md#plperl-database)
- **SPI_cursor_close** — [SPI_cursor_close](spi-spi-cursor-close.md)
- **SPI_cursor_fetch** — [SPI_cursor_fetch](spi-spi-cursor-fetch.md)
- **SPI_cursor_find** — [SPI_cursor_find](spi-spi-cursor-find.md)
- **SPI_cursor_move** — [SPI_cursor_move](spi-spi-cursor-move.md)
- **SPI_cursor_open** — [SPI_cursor_open](spi-spi-cursor-open.md)
- **SPI_cursor_open_with_args** — [SPI_cursor_open_with_args](spi-spi-cursor-open-with-args.md)
- **SPI_cursor_open_with_paramlist** — [SPI_cursor_open_with_paramlist](spi-spi-cursor-open-with-paramlist.md)
- **SPI_cursor_parse_open** — [SPI_cursor_parse_open](spi-spi-cursor-parse-open.md)
- **SPI_exec** — [SPI_exec](spi-spi-exec.md)
- **SPI_execp** — [SPI_execp](spi-spi-execp.md)
- **SPI_execute** — [SPI_execute](spi-spi-execute.md)
- **SPI_execute_extended** — [SPI_execute_extended](spi-spi-execute-extended.md)
- **SPI_execute_plan** — [SPI_execute_plan](spi-spi-execute-plan.md)
- **SPI_execute_plan_extended** — [SPI_execute_plan_extended](spi-spi-execute-plan-extended.md)
- **SPI_execute_plan_with_paramlist** — [SPI_execute_plan_with_paramlist](spi-spi-execute-plan-with-paramlist.md)
- **SPI_execute_with_args** — [SPI_execute_with_args](spi-spi-execute-with-args.md)
- **spi_exec_prepared**
  - in PL/Perl — [Database Access from PL/Perl](plperl-builtins.md#plperl-database)
- **spi_exec_query**
  - in PL/Perl — [Database Access from PL/Perl](plperl-builtins.md#plperl-database)
- **spi_fetchrow**
  - in PL/Perl — [Database Access from PL/Perl](plperl-builtins.md#plperl-database)
- **SPI_finish** — [SPI_finish](spi-spi-finish.md)
- **SPI_fname** — [SPI_fname](spi-spi-fname.md)
- **SPI_fnumber** — [SPI_fnumber](spi-spi-fnumber.md)
- **spi_freeplan**
  - in PL/Perl — [Database Access from PL/Perl](plperl-builtins.md#plperl-database)
- **SPI_freeplan** — [SPI_freeplan](spi-spi-freeplan.md)
- **SPI_freetuple** — [SPI_freetuple](spi-spi-freetuple.md)
- **SPI_freetuptable** — [SPI_freetuptable](spi-spi-freetupletable.md)
- **SPI_getargcount** — [SPI_getargcount](spi-spi-getargcount.md)
- **SPI_getargtypeid** — [SPI_getargtypeid](spi-spi-getargtypeid.md)
- **SPI_getbinval** — [SPI_getbinval](spi-spi-getbinval.md)
- **SPI_getnspname** — [SPI_getnspname](spi-spi-getnspname.md)
- **SPI_getrelname** — [SPI_getrelname](spi-spi-getrelname.md)
- **SPI_gettype** — [SPI_gettype](spi-spi-gettype.md)
- **SPI_gettypeid** — [SPI_gettypeid](spi-spi-gettypeid.md)
- **SPI_getvalue** — [SPI_getvalue](spi-spi-getvalue.md)
- **SPI_is_cursor_plan** — [SPI_is_cursor_plan](spi-spi-is-cursor-plan.md)
- **SPI_keepplan** — [SPI_keepplan](spi-spi-keepplan.md)
- **SPI_modifytuple** — [SPI_modifytuple](spi-spi-modifytuple.md)
- **SPI_palloc** — [SPI_palloc](spi-spi-palloc.md)
- **SPI_pfree** — [SPI_pfree](spi-spi-pfree.md)
- **spi_prepare**
  - in PL/Perl — [Database Access from PL/Perl](plperl-builtins.md#plperl-database)
- **SPI_prepare** — [SPI_prepare](spi-spi-prepare.md)
- **SPI_prepare_cursor** — [SPI_prepare_cursor](spi-spi-prepare-cursor.md)
- **SPI_prepare_extended** — [SPI_prepare_extended](spi-spi-prepare-extended.md)
- **SPI_prepare_params** — [SPI_prepare_params](spi-spi-prepare-params.md)
- **spi_query**
  - in PL/Perl — [Database Access from PL/Perl](plperl-builtins.md#plperl-database)
- **spi_query_prepared**
  - in PL/Perl — [Database Access from PL/Perl](plperl-builtins.md#plperl-database)
- **SPI_register_relation** — [SPI_register_relation](spi-spi-register-relation.md)
- **SPI_register_trigger_data** — [SPI_register_trigger_data](spi-spi-register-trigger-data.md)
- **SPI_repalloc** — [SPI_repalloc](spi-realloc.md)
- **SPI_result_code_string** — [SPI_result_code_string](spi-spi-result-code-string.md)
- **SPI_returntuple** — [SPI_returntuple](spi-spi-returntuple.md)
- **spi_rollback**
  - in PL/Perl — [Database Access from PL/Perl](plperl-builtins.md#plperl-database)
- **SPI_rollback** — [SPI_rollback](spi-spi-rollback.md)
- **SPI_rollback_and_chain** — [SPI_rollback](spi-spi-rollback.md)
- **SPI_saveplan** — [SPI_saveplan](spi-spi-saveplan.md)
- **SPI_scroll_cursor_fetch** — [SPI_scroll_cursor_fetch](spi-spi-scroll-cursor-fetch.md)
- **SPI_scroll_cursor_move** — [SPI_scroll_cursor_move](spi-spi-scroll-cursor-move.md)
- **SPI_start_transaction** — [SPI_start_transaction](spi-spi-start-transaction.md)
- **SPI_unregister_relation** — [SPI_unregister_relation](spi-spi-unregister-relation.md)
- **split_part** — [String Functions and Operators](functions-string.md)
- **SQL/CLI** — [SQL Conformance](features.md)
- **SQL/Foundation** — [SQL Conformance](features.md)
- **SQL/Framework** — [SQL Conformance](features.md)
- **SQL/JRT** — [SQL Conformance](features.md)
- **SQL/JSON**
  - functions and expressions — [JSON Functions and Operators](functions-json.md)
- **SQL/JSON path language** — [The SQL/JSON Path Language](functions-json.md#functions-sqljson-path)
- **SQL/MDA** — [SQL Conformance](features.md)
- **SQL/MED** — [SQL Conformance](features.md)
- **SQL/OLB** — [SQL Conformance](features.md)
- **SQL/PGQ** — [SQL Conformance](features.md)
- **SQL/PSM** — [SQL Conformance](features.md)
- **SQL/Schemata** — [SQL Conformance](features.md)
- **SQL/XML** — [SQL Conformance](features.md)
  - limits and conformance — [XML Limits and Conformance to SQL/XML](xml-limits-conformance.md)
- **sqrt** — [Mathematical Functions and Operators](functions-math.md)
- **ssh** — [Secure TCP/IP Connections with SSH Tunnels](ssh-tunnels.md)
- **SSI** — [Introduction](mvcc-intro.md)
- **SSL**
  - in libpq — [Connection Status Functions](libpq-status.md)
  - with libpq — [Parameter Key Words](libpq-connect.md#libpq-paramkeywords)
  - TLS — [Secure TCP/IP Connections with SSL](ssl-tcp.md), [SSL Support](libpq-ssl.md)
- **ssl configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **sslinfo** — [sslinfo — obtain client SSL information](sslinfo.md)
- **ssl_ca_file configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **ssl_cert_file configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **ssl_cipher** — [Functions Provided](sslinfo.md#sslinfo-functions)
- **ssl_ciphers configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **ssl_client_cert_present** — [Functions Provided](sslinfo.md#sslinfo-functions)
- **ssl_client_dn** — [Functions Provided](sslinfo.md#sslinfo-functions)
- **ssl_client_dn_field** — [Functions Provided](sslinfo.md#sslinfo-functions)
- **ssl_client_serial** — [Functions Provided](sslinfo.md#sslinfo-functions)
- **ssl_crl_dir configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **ssl_crl_file configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **ssl_dh_params_file configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **ssl_extension_info** — [Functions Provided](sslinfo.md#sslinfo-functions)
- **ssl_groups configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **ssl_issuer_dn** — [Functions Provided](sslinfo.md#sslinfo-functions)
- **ssl_issuer_field** — [Functions Provided](sslinfo.md#sslinfo-functions)
- **ssl_is_used** — [Functions Provided](sslinfo.md#sslinfo-functions)
- **ssl_key_file configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **ssl_library configuration parameter** — [Preset Options](runtime-config-preset.md)
- **ssl_max_protocol_version configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **ssl_min_protocol_version configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **ssl_passphrase_command configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **ssl_passphrase_command_supports_reload configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **ssl_prefer_server_ciphers configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **ssl_sni configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **ssl_tls13_ciphers configuration parameter** — [SSL](runtime-config-connection.md#runtime-config-connection-ssl)
- **ssl_version** — [Functions Provided](sslinfo.md#sslinfo-functions)
- **SSPI** — [SSPI Authentication](sspi-auth.md)
- **STABLE** — [Function Volatility Categories](xfunc-volatility.md)
- **standard deviation** — [Aggregate Functions](functions-aggregate.md)
  - population — [Aggregate Functions](functions-aggregate.md)
  - sample — [Aggregate Functions](functions-aggregate.md)
- **standard_conforming_strings configuration parameter** — [Previous PostgreSQL Versions](runtime-config-compatible.md#runtime-config-compatible-version)
- **standby server** — [Log-Shipping Standby Servers](warm-standby.md)
- **standby.signal** — [Archive Recovery](runtime-config-wal.md#runtime-config-wal-archive-recovery), [Standby Server Operation](warm-standby.md#standby-server-operation), [Setting Up a Standby Server](warm-standby.md#standby-server-setup)
  - for hot standby — [Administrator's Overview](hot-standby.md#hot-standby-admin)
  - pg_basebackup --write-recovery-conf — [Options](app-pgbasebackup.md#id-1.9.4.10.6)
- **standby_mode** — *see* standby.signal
- **START TRANSACTION** — [START TRANSACTION](sql-start-transaction.md)
- **starts_with** — [String Functions and Operators](functions-string.md)
- **START_REPLICATION** — [Streaming Replication Protocol](protocol-replication.md)
- **statement_timeout configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **statement_timestamp** — [Date/Time Functions and Operators](functions-datetime.md)
- **statistics** — [Aggregate Functions](functions-aggregate.md), [The Cumulative Statistics System](monitoring-stats.md)
  - of the planner — [Statistics Used by the Planner](planner-stats.md), [Extended Statistics](planner-stats.md#planner-stats-extended), [Updating Planner Statistics](routine-vacuuming.md#vacuum-for-statistics)
- **stats_fetch_consistency configuration parameter** — [Cumulative Query and Index Statistics](runtime-config-statistics.md#runtime-config-cumulative-statistics)
- **stddev** — [Aggregate Functions](functions-aggregate.md)
- **stddev_pop** — [Aggregate Functions](functions-aggregate.md)
- **stddev_samp** — [Aggregate Functions](functions-aggregate.md)
- **STONITH** — [Log-Shipping Standby Servers](warm-standby.md)
- **storage parameters** — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **Streaming Replication** — [Streaming Replication](warm-standby.md#streaming-replication)
- **strict_word_similarity** — [Functions and Operators](pgtrgm.md#pgtrgm-funcs-ops)
- **string** — *see* character string
- **strings**
  - backslash quotes — [Previous PostgreSQL Versions](runtime-config-compatible.md#runtime-config-compatible-version)
  - standard conforming — [Previous PostgreSQL Versions](runtime-config-compatible.md#runtime-config-compatible-version)
- **string_agg** — [Aggregate Functions](functions-aggregate.md)
- **string_to_array** — [String Functions and Operators](functions-string.md)
- **string_to_table** — [String Functions and Operators](functions-string.md)
- **strip** — [Text Search Functions and Operators](functions-textsearch.md), [Manipulating Documents](textsearch-features.md#textsearch-manipulate-tsvector)
- **strpos** — [String Functions and Operators](functions-string.md)
- **subarray** — [`intarray` Functions and Operators](intarray.md#intarray-funcs-ops)
- **subltree** — [Operators and Functions](ltree.md#ltree-ops-funcs)
- **subpath** — [Operators and Functions](ltree.md#ltree-ops-funcs)
- **subplan** — [`EXPLAIN` Basics](using-explain.md#using-explain-basics)
  - hashed — [`EXPLAIN` Basics](using-explain.md#using-explain-basics)
- **subquery** — [Aggregate Functions](tutorial-agg.md), [Scalar Subqueries](sql-expressions.md#sql-syntax-scalar-subqueries), [Subqueries](queries-table-expressions.md#queries-subqueries), [Subquery Expressions](functions-subquery.md)
- **subscript** — [Subscripts](sql-expressions.md#sql-expressions-subscripts)
- **substr** — [String Functions and Operators](functions-string.md), [Binary String Functions and Operators](functions-binarystring.md)
- **substring** — [String Functions and Operators](functions-string.md), [Binary String Functions and Operators](functions-binarystring.md), [Bit String Functions and Operators](functions-bitstring.md), [`SIMILAR TO` Regular Expressions](functions-matching.md#functions-similarto-regexp), [`substring`](functions-matching.md#functions-posix-substring)
- **SUBSTRING_REGEX** — [Differences from SQL Standard and XQuery](functions-matching.md#posix-vs-xquery)
- **subtransactions**
  - in PL/Tcl — [Explicit Subtransactions in PL/Tcl](pltcl-subtransactions.md)
- **subtransaction_buffers configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **sum** — [Aggregate Functions](functions-aggregate.md)
- **summarize_wal configuration parameter** — [WAL Summarization](runtime-config-wal.md#runtime-config-wal-summarization)
- **superuser** — [Accessing a Database](tutorial-accessdb.md), [Role Attributes](role-attributes.md)
- **superuser_reserved_connections configuration parameter** — [Connection Settings](runtime-config-connection.md#runtime-config-connection-settings)
- **support functions**
  - in_range — [B-Tree Support Functions](btree.md#btree-support-funcs)
- **suppress_redundant_updates_trigger** — [Trigger Functions](functions-trigger.md)
- **svals** — [`hstore` Operators and Functions](hstore.md#hstore-ops-funcs)
- **synchronized_standby_slots configuration parameter** — [Primary Server](runtime-config-replication.md#runtime-config-replication-primary)
- **synchronize_seqscans configuration parameter** — [Previous PostgreSQL Versions](runtime-config-compatible.md#runtime-config-compatible-version)
- **synchronous commit** — [Asynchronous Commit](wal-async-commit.md)
- **Synchronous Replication** — [Synchronous Replication](warm-standby.md#synchronous-replication)
- **synchronous_commit configuration parameter** — [Settings](runtime-config-wal.md#runtime-config-wal-settings)
- **synchronous_standby_names configuration parameter** — [Primary Server](runtime-config-replication.md#runtime-config-replication-primary)
- **sync_replication_slots configuration parameter** — [Standby Servers](runtime-config-replication.md#runtime-config-replication-standby)
- **syntax**
  - SQL — [SQL Syntax](sql-syntax.md)
- **syslog_facility configuration parameter** — [Where to Log](runtime-config-logging.md#runtime-config-logging-where)
- **syslog_ident configuration parameter** — [Where to Log](runtime-config-logging.md#runtime-config-logging-where)
- **syslog_sequence_numbers configuration parameter** — [Where to Log](runtime-config-logging.md#runtime-config-logging-where)
- **syslog_split_messages configuration parameter** — [Where to Log](runtime-config-logging.md#runtime-config-logging-where)
- **system catalog**
  - schema — [The System Catalog Schema](ddl-schemas.md#ddl-schemas-catalog)
- **system time** — [System Time](ddl-temporal-tables.md#ddl-system-time)
- **systemd** — [PostgreSQL Features](install-make.md#configure-options-features), [PostgreSQL Features](install-meson.md#meson-options-features), [Starting the Database Server](server-start.md)
  - RemoveIPC — [systemd RemoveIPC](kernel-resources.md#systemd-removeipc)
- **system_user** — [Session Information Functions](functions-info.md#functions-info-session)

## T

- **table** — [Concepts](tutorial-concepts.md), [Table Basics](ddl-basics.md)
  - creating — [Table Basics](ddl-basics.md)
  - inheritance — [Inheritance](ddl-inherit.md)
  - modifying — [Modifying Tables](ddl-alter.md)
  - partitioning — [Table Partitioning](ddl-partitioning.md)
  - removing — [Table Basics](ddl-basics.md)
  - renaming — [Renaming a Table](ddl-alter.md#ddl-alter-renaming-table)
- **Table Access Method** — [Table Access Method Interface Definition](tableam.md)
- **TABLE command** — [SELECT](sql-select.md)
- **table expression** — [Table Expressions](queries-table-expressions.md)
- **table function** — [Table Functions](queries-table-expressions.md#queries-tablefunctions)
  - XMLTABLE — [`xmltable`](functions-xml.md#functions-xml-processing-xmltable)
- **table sampling method** — [Writing a Table Sampling Method](tablesample-method.md)
- **tableam**
  - Table Access Method — [Table Access Method Interface Definition](tableam.md)
- **tablefunc** — [tablefunc — functions that return tables (`crosstab` and others)](tablefunc.md)
- **tableoid** — [System Columns](ddl-system-columns.md)
- **TABLESAMPLE method** — [Writing a Table Sampling Method](tablesample-method.md)
- **tablespace** — [Tablespaces](manage-ag-tablespaces.md)
  - default — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
  - temporary — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **table_am_handler** — [Pseudo-Types](datatype-pseudo.md)
- **tan** — [Mathematical Functions and Operators](functions-math.md)
- **tand** — [Mathematical Functions and Operators](functions-math.md)
- **tanh** — [Mathematical Functions and Operators](functions-math.md)
- **target list** — [The Query Tree](querytree.md)
- **Tcl** — [PL/Tcl — Tcl Procedural Language](pltcl.md)
- **tcn** — [tcn — a trigger function to notify listeners of changes to table content](tcn.md)
- **tcp_keepalives_count configuration parameter** — [TCP Settings](runtime-config-connection.md#runtime-config-tcp-settings)
- **tcp_keepalives_idle configuration parameter** — [TCP Settings](runtime-config-connection.md#runtime-config-tcp-settings)
- **tcp_keepalives_interval configuration parameter** — [TCP Settings](runtime-config-connection.md#runtime-config-tcp-settings)
- **tcp_user_timeout configuration parameter** — [TCP Settings](runtime-config-connection.md#runtime-config-tcp-settings)
- **template0** — [Creating a Database](manage-ag-createdb.md), [Template Databases](manage-ag-templatedbs.md)
- **template1** — [Creating a Database](manage-ag-createdb.md), [Template Databases](manage-ag-templatedbs.md)
- **temporal** — [Temporal Tables](ddl-temporal-tables.md)
- **temp_buffers configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **temp_file_limit configuration parameter** — [Disk](runtime-config-resource.md#runtime-config-resource-disk)
- **temp_tablespaces configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **test** — [Regression Tests](regress.md)
- **test_decoding** — [test_decoding — SQL-based test/example module for WAL logical decoding](test-decoding.md)
- **text** — [Character Types](datatype-character.md), [Network Address Functions and Operators](functions-net.md)
- **text search** — [Full Text Search](textsearch.md)
  - data types — [Text Search Types](datatype-textsearch.md)
  - functions and operators — [Text Search Functions and Operators](functions-textsearch.md)
  - indexes — [Preferred Index Types for Text Search](textsearch-indexes.md)
- **text2ltree** — [Operators and Functions](ltree.md#ltree-ops-funcs)
- **threads**
  - with libpq — [Behavior in Threaded Programs](libpq-threading.md)
- **tid** — [Object Identifier Types](datatype-oid.md)
- **TID**
  - functions — [TID Functions](functions-tid.md)
- **tid_block** — [TID Functions](functions-tid.md)
- **tid_offset** — [TID Functions](functions-tid.md)
- **time** — [Date/Time Types](datatype-datetime.md), [Times](datatype-datetime.md#datatype-datetime-input-times)
  - constants — [Special Values](datatype-datetime.md#datatype-datetime-special-values)
  - current — [Current Date/Time](functions-datetime.md#functions-datetime-current)
  - output format — [Date/Time Output](datatype-datetime.md#datatype-datetime-output); *see also* formatting
- **time span** — [Date/Time Types](datatype-datetime.md)
- **time with time zone** — [Date/Time Types](datatype-datetime.md), [Times](datatype-datetime.md#datatype-datetime-input-times)
- **time without time zone** — [Date/Time Types](datatype-datetime.md), [Times](datatype-datetime.md#datatype-datetime-input-times)
- **time zone** — [Time Zones](datatype-datetime.md#datatype-timezones), [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)
  - conversion — [`AT TIME ZONE` and `AT LOCAL`](functions-datetime.md#functions-datetime-zoneconvert)
  - input abbreviations — [Date/Time Configuration Files](datetime-config-files.md)
  - POSIX-style specification — [POSIX Time Zone Specifications](datetime-posix-timezone-specs.md)
- **time zone data** — [Build Process Details](install-make.md#configure-options-build-process), [Build Process Details](install-meson.md#meson-options-build-process)
- **time zone names** — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)
- **Time-Stamp Counter** — *see* TSC
- **timelines** — [Timelines](continuous-archiving.md#backup-timelines)
- **TIMELINE_HISTORY** — [Streaming Replication Protocol](protocol-replication.md)
- **timeofday** — [Date/Time Functions and Operators](functions-datetime.md)
- **timeout**
  - client authentication — [Authentication](runtime-config-connection.md#runtime-config-connection-authentication)
  - deadlock — [Lock Management](runtime-config-locks.md)
- **timestamp** — [Date/Time Types](datatype-datetime.md), [Time Stamps](datatype-datetime.md#datatype-datetime-input-time-stamps)
- **timestamp with time zone** — [Date/Time Types](datatype-datetime.md), [Time Stamps](datatype-datetime.md#datatype-datetime-input-time-stamps)
- **timestamp without time zone** — [Date/Time Types](datatype-datetime.md), [Time Stamps](datatype-datetime.md#datatype-datetime-input-time-stamps)
- **timestamptz** — [Date/Time Types](datatype-datetime.md)
- **TimeZone configuration parameter** — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)
- **timezone_abbreviations configuration parameter** — [Locale and Formatting](runtime-config-client.md#runtime-config-client-format)
- **timing_clock_source configuration parameter** — [Timing](runtime-config-resource.md#runtime-config-resource-time)
- **TOAST** — [TOAST](storage-toast.md)
  - and user-defined types — [TOAST Considerations](xtypes.md#xtypes-toast)
  - per-column storage settings — [Description](sql-altertable.md#id-1.9.3.36.5), [Parameters](sql-createtable.md#id-1.9.3.87.6)
  - per-type storage settings — [Description](sql-altertype.md#id-1.9.3.43.5)
  - versus large objects — [Introduction](lo-intro.md)
- **toast_tuple_target storage parameter** — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **token** — [Lexical Structure](sql-syntax-lexical.md)
- **to_ascii** — [String Functions and Operators](functions-string.md)
- **to_bin** — [String Functions and Operators](functions-string.md)
- **to_char** — [Data Type Formatting Functions](functions-formatting.md)
  - and locales — [Behavior](locale.md#locale-behavior)
- **to_date** — [Data Type Formatting Functions](functions-formatting.md)
- **to_hex** — [String Functions and Operators](functions-string.md)
- **to_json** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **to_jsonb** — [Processing and Creating JSON Data](functions-json.md#functions-json-processing)
- **to_number** — [Data Type Formatting Functions](functions-formatting.md)
- **to_oct** — [String Functions and Operators](functions-string.md)
- **to_regclass** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **to_regcollation** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **to_regdatabase** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **to_regnamespace** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **to_regoper** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **to_regoperator** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **to_regproc** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **to_regprocedure** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **to_regrole** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **to_regtype** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **to_regtypemod** — [System Catalog Information Functions](functions-info.md#functions-info-catalog)
- **to_timestamp** — [Data Type Formatting Functions](functions-formatting.md), [Date/Time Functions and Operators](functions-datetime.md)
- **to_tsquery** — [Text Search Functions and Operators](functions-textsearch.md), [Parsing Queries](textsearch-controls.md#textsearch-parsing-queries)
- **to_tsvector** — [Text Search Functions and Operators](functions-textsearch.md), [Parsing Documents](textsearch-controls.md#textsearch-parsing-documents)
- **trace_locks configuration parameter** — [Developer Options](runtime-config-developer.md)
- **trace_lock_oidmin configuration parameter** — [Developer Options](runtime-config-developer.md)
- **trace_lock_table configuration parameter** — [Developer Options](runtime-config-developer.md)
- **trace_lwlocks configuration parameter** — [Developer Options](runtime-config-developer.md)
- **trace_notify configuration parameter** — [Developer Options](runtime-config-developer.md)
- **trace_sort configuration parameter** — [Developer Options](runtime-config-developer.md)
- **trace_userlocks configuration parameter** — [Developer Options](runtime-config-developer.md)
- **track_activities configuration parameter** — [Cumulative Query and Index Statistics](runtime-config-statistics.md#runtime-config-cumulative-statistics)
- **track_activity_query_size configuration parameter** — [Cumulative Query and Index Statistics](runtime-config-statistics.md#runtime-config-cumulative-statistics)
- **track_commit_timestamp configuration parameter** — [Sending Servers](runtime-config-replication.md#runtime-config-replication-sender)
- **track_cost_delay_timing configuration parameter** — [Cumulative Query and Index Statistics](runtime-config-statistics.md#runtime-config-cumulative-statistics)
- **track_counts configuration parameter** — [Cumulative Query and Index Statistics](runtime-config-statistics.md#runtime-config-cumulative-statistics)
- **track_functions configuration parameter** — [Cumulative Query and Index Statistics](runtime-config-statistics.md#runtime-config-cumulative-statistics)
- **track_io_timing configuration parameter** — [Cumulative Query and Index Statistics](runtime-config-statistics.md#runtime-config-cumulative-statistics)
- **track_wal_io_timing configuration parameter** — [Cumulative Query and Index Statistics](runtime-config-statistics.md#runtime-config-cumulative-statistics)
- **transaction** — [Transactions](tutorial-transactions.md)
- **transaction ID**
  - wraparound — [Preventing Transaction ID Wraparound Failures](routine-vacuuming.md#vacuum-for-wraparound)
- **transaction isolation** — [Transaction Isolation](transaction-iso.md)
- **transaction isolation level** — [Transaction Isolation](transaction-iso.md), [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
  - read committed — [Read Committed Isolation Level](transaction-iso.md#xact-read-committed)
  - repeatable read — [Repeatable Read Isolation Level](transaction-iso.md#xact-repeatable-read)
  - serializable — [Serializable Isolation Level](transaction-iso.md#xact-serializable)
  - setting — [SET TRANSACTION](sql-set-transaction.md)
  - setting default — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **transaction log** — *see* WAL
- **transaction_buffers configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **transaction_deferrable configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **transaction_isolation configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **transaction_read_only configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **transaction_timeout configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **transaction_timestamp** — [Date/Time Functions and Operators](functions-datetime.md)
- **transform_null_equals configuration parameter** — [Platform and Client Compatibility](runtime-config-compatible.md#runtime-config-compatible-clients)
- **transition tables** — [CREATE TRIGGER](sql-createtrigger.md); *see also* ephemeral named relation
  - implementation in PLs — [SPI_register_trigger_data](spi-spi-register-trigger-data.md)
  - referencing from C trigger — [Writing Trigger Functions in C](trigger-interface.md)
- **translate** — [String Functions and Operators](functions-string.md)
- **TRANSLATE_REGEX** — [Differences from SQL Standard and XQuery](functions-matching.md#posix-vs-xquery)
- **transparent
        huge pages** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **trigger** — [Pseudo-Types](datatype-pseudo.md), [Triggers](triggers.md)
  - arguments for trigger functions — [Overview of Trigger Behavior](trigger-definition.md)
  - constraint trigger — [Description](sql-createtrigger.md#id-1.9.3.95.6)
  - for updating a derived tsvector column — [Triggers for Automatic Updates](textsearch-features.md#textsearch-update-triggers)
  - in C — [Writing Trigger Functions in C](trigger-interface.md)
  - in PL/pgSQL — [Trigger Functions](plpgsql-trigger.md)
  - in PL/Python — [Trigger Functions](plpython-trigger.md)
  - in PL/Tcl — [Trigger Functions in PL/Tcl](pltcl-trigger.md)
  - compared with rules — [Rules Versus Triggers](rules-triggers.md)
- **triggered_change_notification** — [tcn — a trigger function to notify listeners of changes to table content](tcn.md)
- **trim** — [String Functions and Operators](functions-string.md), [Binary String Functions and Operators](functions-binarystring.md)
- **trim_array** — [Array Functions and Operators](functions-array.md)
- **trim_scale** — [Mathematical Functions and Operators](functions-math.md)
- **true** — [Boolean Type](datatype-boolean.md)
- **trunc** — [Mathematical Functions and Operators](functions-math.md), [Network Address Functions and Operators](functions-net.md)
- **TRUNCATE** — [TRUNCATE](sql-truncate.md)
- **trusted**
  - PL/Perl — [Trusted and Untrusted PL/Perl](plperl-trusted.md)
- **TSC** — [Timing](runtime-config-resource.md#runtime-config-resource-time)
- **tsm_handler** — [Pseudo-Types](datatype-pseudo.md)
- **tsm_system_rows** — [tsm_system_rows — the `SYSTEM_ROWS` sampling method for `TABLESAMPLE`](tsm-system-rows.md)
- **tsm_system_time** — [tsm_system_time — the `SYSTEM_TIME` sampling method for `TABLESAMPLE`](tsm-system-time.md)
- **tsquery (data type)** — [`tsquery`](datatype-textsearch.md#datatype-tsquery)
- **tsquery_phrase** — [Text Search Functions and Operators](functions-textsearch.md), [Manipulating Queries](textsearch-features.md#textsearch-manipulate-tsquery)
- **tsvector (data type)** — [`tsvector`](datatype-textsearch.md#datatype-tsvector)
- **tsvector concatenation** — [Manipulating Documents](textsearch-features.md#textsearch-manipulate-tsvector)
- **tsvector_to_array** — [Text Search Functions and Operators](functions-textsearch.md)
- **tsvector_update_trigger** — [Trigger Functions](functions-trigger.md)
- **tsvector_update_trigger_column** — [Trigger Functions](functions-trigger.md)
- **ts_debug** — [Text Search Functions and Operators](functions-textsearch.md), [Configuration Testing](textsearch-debugging.md#textsearch-configuration-testing)
- **ts_delete** — [Text Search Functions and Operators](functions-textsearch.md)
- **ts_filter** — [Text Search Functions and Operators](functions-textsearch.md)
- **ts_headline** — [Text Search Functions and Operators](functions-textsearch.md), [Highlighting Results](textsearch-controls.md#textsearch-headline)
- **ts_lexize** — [Text Search Functions and Operators](functions-textsearch.md), [Dictionary Testing](textsearch-debugging.md#textsearch-dictionary-testing)
- **ts_parse** — [Text Search Functions and Operators](functions-textsearch.md), [Parser Testing](textsearch-debugging.md#textsearch-parser-testing)
- **ts_rank** — [Text Search Functions and Operators](functions-textsearch.md), [Ranking Search Results](textsearch-controls.md#textsearch-ranking)
- **ts_rank_cd** — [Text Search Functions and Operators](functions-textsearch.md), [Ranking Search Results](textsearch-controls.md#textsearch-ranking)
- **ts_rewrite** — [Text Search Functions and Operators](functions-textsearch.md), [Query Rewriting](textsearch-features.md#textsearch-query-rewriting)
- **ts_stat** — [Text Search Functions and Operators](functions-textsearch.md), [Gathering Document Statistics](textsearch-features.md#textsearch-statistics)
- **ts_token_type** — [Text Search Functions and Operators](functions-textsearch.md), [Parser Testing](textsearch-debugging.md#textsearch-parser-testing)
- **tuple_data_split** — [Heap Functions](pageinspect.md#pageinspect-heap-funcs)
- **txid_current** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **txid_current_if_assigned** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **txid_current_snapshot** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **txid_snapshot_xip** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **txid_snapshot_xmax** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **txid_snapshot_xmin** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **txid_status** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **txid_visible_in_snapshot** — [Transaction ID and Snapshot Information Functions](functions-info.md#functions-info-snapshot)
- **type** — *see* data type
- **type cast** — [Numeric Constants](sql-syntax-lexical.md#sql-syntax-constants-numeric), [Type Casts](sql-expressions.md#sql-syntax-type-casts)
- **typedef**
  - in ECPG — [Typedefs](ecpg-variables.md#ecpg-variables-nonprimitive-c-typedefs)

## U

- **UESCAPE** — [Identifiers and Key Words](sql-syntax-lexical.md#sql-syntax-identifiers), [String Constants with Unicode Escapes](sql-syntax-lexical.md#sql-syntax-strings-uescape)
- **unaccent** — [unaccent — a text search dictionary which removes diacritics](unaccent.md), [Functions](unaccent.md#unaccent-functions)
- **Unicode escape**
  - in identifiers — [Identifiers and Key Words](sql-syntax-lexical.md#sql-syntax-identifiers)
  - in string constants — [String Constants with Unicode Escapes](sql-syntax-lexical.md#sql-syntax-strings-uescape)
- **Unicode normalization** — [String Functions and Operators](functions-string.md), [String Functions and Operators](functions-string.md)
- **unicode_assigned** — [String Functions and Operators](functions-string.md)
- **unicode_version** — [Version Information Functions](functions-info.md#functions-info-version)
- **UNION** — [Combining Queries (`UNION`, `INTERSECT`, `EXCEPT`)](queries-union.md)
  - determination of result type — [`UNION`, `CASE`, and Related Constructs](typeconv-union-case.md)
- **uniq** — [`intarray` Functions and Operators](intarray.md#intarray-funcs-ops)
- **unique constraint** — [Unique Constraints](ddl-constraints.md#ddl-constraints-unique-constraints)
- **unistr** — [String Functions and Operators](functions-string.md)
- **Unix domain socket** — [Parameter Key Words](libpq-connect.md#libpq-paramkeywords)
- **unix_socket_directories configuration parameter** — [Connection Settings](runtime-config-connection.md#runtime-config-connection-settings)
- **unix_socket_group configuration parameter** — [Connection Settings](runtime-config-connection.md#runtime-config-connection-settings)
- **unix_socket_permissions configuration parameter** — [Connection Settings](runtime-config-connection.md#runtime-config-connection-settings)
- **unknown** — [Pseudo-Types](datatype-pseudo.md)
- **UNLISTEN** — [UNLISTEN](sql-unlisten.md)
- **unnest** — [Array Functions and Operators](functions-array.md)
  - for multirange — [Range/Multirange Functions and Operators](functions-range.md)
  - for tsvector — [Text Search Functions and Operators](functions-textsearch.md)
- **unqualified name** — [The Schema Search Path](ddl-schemas.md#ddl-schemas-path)
- **updatable views** — [Updatable Views](sql-createview.md#sql-createview-updatable-views)
- **UPDATE** — [Updates](tutorial-update.md), [Updating Data](dml-update.md), [UPDATE](sql-update.md)
  - RETURNING — [Returning Data from Modified Rows](dml-returning.md)
- **update_process_title configuration parameter** — [Process Title](runtime-config-logging.md#runtime-config-logging-proc-title)
- **updating** — [Updating Data](dml-update.md)
- **upgrading** — [Upgrading a PostgreSQL Cluster](upgrading.md)
- **UPLOAD_MANIFEST** — [Streaming Replication Protocol](protocol-replication.md)
- **upper** — [String Functions and Operators](functions-string.md), [Range/Multirange Functions and Operators](functions-range.md), [Range/Multirange Functions and Operators](functions-range.md)
  - and locales — [Behavior](locale.md#locale-behavior)
- **upper_inc** — [Range/Multirange Functions and Operators](functions-range.md), [Range/Multirange Functions and Operators](functions-range.md)
- **upper_inf** — [Range/Multirange Functions and Operators](functions-range.md), [Range/Multirange Functions and Operators](functions-range.md)
- **UPSERT** — [`ON CONFLICT` Clause](sql-insert.md#sql-on-conflict)
- **URI** — [Connection Strings](libpq-connect.md#libpq-connstring)
- **user** — [Session Information Functions](functions-info.md#functions-info-session), [Database Roles](database-roles.md)
  - current — [Session Information Functions](functions-info.md#functions-info-session)
- **user mapping** — [Foreign Data](ddl-foreign-data.md)
- **User name maps** — [User Name Maps](auth-username-maps.md)
- **user_catalog_table storage parameter** — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **UUID** — [UUID Type](datatype-uuid.md), [PostgreSQL Features](install-make.md#configure-options-features), [PostgreSQL Features](install-meson.md#meson-options-features)
  - generating — [UUID Functions](functions-uuid.md)
- **uuid-ossp** — [uuid-ossp — a UUID generator](uuid-ossp.md)
- **uuidv4** — [UUID Functions](functions-uuid.md)
- **uuidv7** — [UUID Functions](functions-uuid.md)
- **uuid_extract_timestamp** — [UUID Functions](functions-uuid.md)
- **uuid_extract_version** — [UUID Functions](functions-uuid.md)
- **uuid_generate_v1** — [`uuid-ossp` Functions](uuid-ossp.md#uuid-ossp-functions-sect)
- **uuid_generate_v1mc** — [`uuid-ossp` Functions](uuid-ossp.md#uuid-ossp-functions-sect)
- **uuid_generate_v3** — [`uuid-ossp` Functions](uuid-ossp.md#uuid-ossp-functions-sect)

## V

- **vacuum** — [Routine Vacuuming](routine-vacuuming.md)
  - configuration parameters — [Vacuuming](runtime-config-vacuum.md)
- **VACUUM** — [VACUUM](sql-vacuum.md)
- **vacuumdb** — [vacuumdb](app-vacuumdb.md)
- **vacuumlo** — [vacuumlo](vacuumlo.md)
- **vacuum_buffer_usage_limit configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **vacuum_cost_delay configuration parameter** — [Cost-based Vacuum Delay](runtime-config-vacuum.md#runtime-config-resource-vacuum-cost)
- **vacuum_cost_limit configuration parameter** — [Cost-based Vacuum Delay](runtime-config-vacuum.md#runtime-config-resource-vacuum-cost)
- **vacuum_cost_page_dirty configuration parameter** — [Cost-based Vacuum Delay](runtime-config-vacuum.md#runtime-config-resource-vacuum-cost)
- **vacuum_cost_page_hit configuration parameter** — [Cost-based Vacuum Delay](runtime-config-vacuum.md#runtime-config-resource-vacuum-cost)
- **vacuum_cost_page_miss configuration parameter** — [Cost-based Vacuum Delay](runtime-config-vacuum.md#runtime-config-resource-vacuum-cost)
- **vacuum_failsafe_age configuration parameter** — [Freezing](runtime-config-vacuum.md#runtime-config-vacuum-freezing)
- **vacuum_freeze_min_age configuration parameter** — [Freezing](runtime-config-vacuum.md#runtime-config-vacuum-freezing)
- **vacuum_freeze_table_age configuration parameter** — [Freezing](runtime-config-vacuum.md#runtime-config-vacuum-freezing)
- **vacuum_index_cleanup storage parameter** — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **vacuum_max_eager_freeze_failure_rate**
  - configuration parameter — [Freezing](runtime-config-vacuum.md#runtime-config-vacuum-freezing)
  - storage parameter — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **vacuum_multixact_failsafe_age configuration parameter** — [Freezing](runtime-config-vacuum.md#runtime-config-vacuum-freezing)
- **vacuum_multixact_freeze_min_age configuration parameter** — [Freezing](runtime-config-vacuum.md#runtime-config-vacuum-freezing)
- **vacuum_multixact_freeze_table_age configuration parameter** — [Freezing](runtime-config-vacuum.md#runtime-config-vacuum-freezing)
- **vacuum_truncate**
  - configuration parameter — [Default Behavior](runtime-config-vacuum.md#runtime-config-vacuum-default)
  - storage parameter — [Storage Parameters](sql-createtable.md#sql-createtable-storage-parameters)
- **value expression** — [Value Expressions](sql-expressions.md)
- **VALUES** — [`VALUES` Lists](queries-values.md), [VALUES](sql-values.md)
  - determination of result type — [`UNION`, `CASE`, and Related Constructs](typeconv-union-case.md)
- **varchar** — [Character Types](datatype-character.md)
- **variadic function** — [SQL Functions with Variable Numbers of Arguments](xfunc-sql.md#xfunc-sql-variadic-functions)
- **variance** — [Aggregate Functions](functions-aggregate.md)
  - population — [Aggregate Functions](functions-aggregate.md)
  - sample — [Aggregate Functions](functions-aggregate.md)
- **var_pop** — [Aggregate Functions](functions-aggregate.md)
- **var_samp** — [Aggregate Functions](functions-aggregate.md)
- **version** — [Accessing a Database](tutorial-accessdb.md), [Version Information Functions](functions-info.md#functions-info-version)
  - compatibility — [Upgrading a PostgreSQL Cluster](upgrading.md)
- **view** — [Views](tutorial-views.md)
  - implementation through rules — [Views and the Rule System](rules-views.md)
  - materialized — [Materialized Views](rules-materializedviews.md)
  - updating — [Cooperation with Views](rules-update.md#rules-update-views)
- **Visibility Map** — [Visibility Map](storage-vm.md)
- **Visual Studio**
  - installation on — [Visual Studio](installation-platform-notes.md#installation-notes-visual-studio)
- **VM** — *see* Visibility Map
- **void** — [Pseudo-Types](datatype-pseudo.md)
- **VOLATILE** — [Function Volatility Categories](xfunc-volatility.md)
- **volatility**
  - functions — [Function Volatility Categories](xfunc-volatility.md)
- **VPATH** — [Installation Procedure](install-make.md#install-procedure-make), [Extension Building Infrastructure](extend-pgxs.md)

## W

- **WAIT FOR** — [WAIT FOR](sql-wait-for.md)
- **WAL** — [Write-Ahead Logging (WAL)](wal-intro.md)
- **wal_block_size configuration parameter** — [Preset Options](runtime-config-preset.md)
- **wal_buffers configuration parameter** — [Settings](runtime-config-wal.md#runtime-config-wal-settings)
- **wal_compression configuration parameter** — [Settings](runtime-config-wal.md#runtime-config-wal-settings)
- **wal_consistency_checking configuration parameter** — [Developer Options](runtime-config-developer.md)
- **wal_debug configuration parameter** — [Developer Options](runtime-config-developer.md)
- **wal_decode_buffer_size configuration parameter** — [Recovery](runtime-config-wal.md#runtime-config-wal-recovery)
- **wal_init_zero configuration parameter** — [Settings](runtime-config-wal.md#runtime-config-wal-settings)
- **wal_keep_size configuration parameter** — [Sending Servers](runtime-config-replication.md#runtime-config-replication-sender)
- **wal_level configuration parameter** — [Settings](runtime-config-wal.md#runtime-config-wal-settings)
- **wal_log_hints configuration parameter** — [Settings](runtime-config-wal.md#runtime-config-wal-settings)
- **wal_receiver_create_temp_slot configuration parameter** — [Standby Servers](runtime-config-replication.md#runtime-config-replication-standby)
- **wal_receiver_status_interval configuration parameter** — [Standby Servers](runtime-config-replication.md#runtime-config-replication-standby)
- **wal_receiver_timeout configuration parameter** — [Standby Servers](runtime-config-replication.md#runtime-config-replication-standby)
- **wal_recycle configuration parameter** — [Settings](runtime-config-wal.md#runtime-config-wal-settings)
- **wal_retrieve_retry_interval configuration parameter** — [Standby Servers](runtime-config-replication.md#runtime-config-replication-standby)
- **wal_segment_size configuration parameter** — [Preset Options](runtime-config-preset.md)
- **wal_sender_shutdown_timeout configuration parameter** — [Sending Servers](runtime-config-replication.md#runtime-config-replication-sender)
- **wal_sender_timeout configuration parameter** — [Sending Servers](runtime-config-replication.md#runtime-config-replication-sender)
- **wal_skip_threshold configuration parameter** — [Settings](runtime-config-wal.md#runtime-config-wal-settings)
- **wal_summary_keep_time configuration parameter** — [WAL Summarization](runtime-config-wal.md#runtime-config-wal-summarization)
- **wal_sync_method configuration parameter** — [Settings](runtime-config-wal.md#runtime-config-wal-settings)
- **wal_writer_delay configuration parameter** — [Settings](runtime-config-wal.md#runtime-config-wal-settings)
- **wal_writer_flush_after configuration parameter** — [Settings](runtime-config-wal.md#runtime-config-wal-settings)
- **warm standby** — [Log-Shipping Standby Servers](warm-standby.md)
- **websearch_to_tsquery** — [Text Search Functions and Operators](functions-textsearch.md)
- **WHERE** — [The `WHERE` Clause](queries-table-expressions.md#queries-where)
- **where to log** — [Where to Log](runtime-config-logging.md#runtime-config-logging-where)
- **WHILE**
  - in PL/pgSQL — [`WHILE`](plpgsql-control-structures.md#plpgsql-control-structures-loops-while)
- **width** — [Geometric Functions and Operators](functions-geometry.md)
- **width_bucket** — [Mathematical Functions and Operators](functions-math.md)
- **window function** — [Window Functions](tutorial-window.md)
  - built-in — [Window Functions](functions-window.md)
  - invocation — [Window Function Calls](sql-expressions.md#syntax-window-functions)
  - order of execution — [Window Function Processing](queries-table-expressions.md#queries-window)
- **WITH**
  - in SELECT — [`WITH` Queries (Common Table Expressions)](queries-with.md), [SELECT](sql-select.md)
- **WITH CHECK OPTION** — [Parameters](sql-createview.md#id-1.9.3.99.6)
- **WITHIN GROUP** — [Aggregate Expressions](sql-expressions.md#syntax-aggregates)
- **witness server** — [Log-Shipping Standby Servers](warm-standby.md)
- **word_similarity** — [Functions and Operators](pgtrgm.md#pgtrgm-funcs-ops)
- **work_mem configuration parameter** — [Memory](runtime-config-resource.md#runtime-config-resource-memory)
- **wraparound**
  - of multixact IDs — [Multixacts and Wraparound](routine-vacuuming.md#vacuum-for-multixact-wraparound)
  - of transaction IDs — [Preventing Transaction ID Wraparound Failures](routine-vacuuming.md#vacuum-for-wraparound)

## X

- **xid** — [Object Identifier Types](datatype-oid.md)
- **xid8** — [Object Identifier Types](datatype-oid.md)
- **xmax** — [System Columns](ddl-system-columns.md)
- **xmin** — [System Columns](ddl-system-columns.md)
- **XML** — [XML Type](datatype-xml.md)
- **XML export** — [Mapping Tables to XML](functions-xml.md#functions-xml-mapping)
- **XML Functions** — [XML Functions](functions-xml.md)
- **XML option** — [Creating XML Values](datatype-xml.md#datatype-xml-creating), [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **xml2** — [xml2 — XPath querying and XSLT functionality](xml2.md)
- **xmlagg** — [`xmlagg`](functions-xml.md#functions-xml-xmlagg), [Aggregate Functions](functions-aggregate.md)
- **xmlbinary configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **xmlcomment** — [`xmlcomment`](functions-xml.md#functions-producing-xml-xmlcomment)
- **xmlconcat** — [`xmlconcat`](functions-xml.md#functions-producing-xml-xmlconcat)
- **xmlelement** — [`xmlelement`](functions-xml.md#functions-producing-xml-xmlelement)
- **XMLEXISTS** — [`XMLEXISTS`](functions-xml.md#xml-exists)
- **xmlforest** — [`xmlforest`](functions-xml.md#functions-producing-xml-xmlforest)
- **xmloption configuration parameter** — [Statement Behavior](runtime-config-client.md#runtime-config-client-statement)
- **xmlparse** — [Creating XML Values](datatype-xml.md#datatype-xml-creating)
- **xmlpi** — [`xmlpi`](functions-xml.md#functions-producing-xml-xmlpi)
- **xmlroot** — [`xmlroot`](functions-xml.md#functions-producing-xml-xmlroot)
- **xmlserialize** — [Creating XML Values](datatype-xml.md#datatype-xml-creating)
- **xmltable** — [`xmltable`](functions-xml.md#functions-xml-processing-xmltable)
- **xmltext** — [`xmltext`](functions-xml.md#functions-producing-xml-xmltext)
- **xml_is_well_formed** — [`xml_is_well_formed`](functions-xml.md#xml-is-well-formed)
- **xml_is_well_formed_content** — [`xml_is_well_formed`](functions-xml.md#xml-is-well-formed)
- **xml_is_well_formed_document** — [`xml_is_well_formed`](functions-xml.md#xml-is-well-formed)
- **XPath** — [`xpath`](functions-xml.md#functions-xml-processing-xpath)
- **xpath_exists** — [`xpath_exists`](functions-xml.md#functions-xml-processing-xpath-exists)
- **xpath_table** — [`xpath_table`](xml2.md#xml2-xpath-table)
- **XQuery regular expressions** — [Differences from SQL Standard and XQuery](functions-matching.md#posix-vs-xquery)
- **xslt_process** — [`xslt_process`](xml2.md#xml2-xslt-xslt-process)

## Y

- **yacc** — [Requirements](install-requirements.md)

## Z

- **zero_damaged_pages configuration parameter** — [Developer Options](runtime-config-developer.md)
- **zlib** — [Requirements](install-requirements.md), [Anti-Features](install-make.md#configure-options-anti-features), [Anti-Features](install-meson.md#meson-options-anti-features)