--- title: "Acronyms" id: acronyms pg_version: "20devel" --- # Acronyms This is a list of acronyms commonly used in the PostgreSQL documentation and in discussions about PostgreSQL. **AIO** [Asynchronous I/O](glossary.md#glossary-aio) **ACL** [Access Control List](https://en.wikipedia.org/wiki/Access-control_list) **AM** [Access Method](glossary.md#glossary-am) **ANSI** [American National Standards Institute](https://en.wikipedia.org/wiki/American_National_Standards_Institute) **API** [Application Programming Interface](https://en.wikipedia.org/wiki/API) **ASCII** [American Standard Code for Information Interchange](https://en.wikipedia.org/wiki/ASCII) **BKI** [Backend Interface](bki.md) **CA** [Certificate Authority](https://en.wikipedia.org/wiki/Certificate_authority) **CIDR** [Classless Inter-Domain Routing](https://en.wikipedia.org/wiki/Classless_Inter-Domain_Routing) **CPAN** [Comprehensive Perl Archive Network](https://www.cpan.org/) **CRL** [Certificate Revocation List](https://en.wikipedia.org/wiki/Certificate_revocation_list) **CSV** [Comma Separated Values](https://en.wikipedia.org/wiki/Comma-separated_values) **CTE** [Common Table Expression](queries-with.md) **CVE** [Common Vulnerabilities and Exposures](https://cve.mitre.org/) **DBA** [Database Administrator](https://en.wikipedia.org/wiki/Database_administrator) **DBI** [Database Interface (Perl)](https://dbi.perl.org/) **DBMS** [Database Management System](https://en.wikipedia.org/wiki/Database#Database_management_system) **DDL** [Data Definition Language](https://en.wikipedia.org/wiki/Data_definition_language), SQL commands such as `CREATE TABLE`, `ALTER USER` **DML** [Data Manipulation Language](https://en.wikipedia.org/wiki/Data_manipulation_language), SQL commands such as `INSERT`, `UPDATE`, `DELETE` **DST** [Daylight Saving Time](https://en.wikipedia.org/wiki/Daylight_saving_time) **ECPG** [Embedded C for PostgreSQL](ecpg.md) **ESQL** [Embedded SQL](https://en.wikipedia.org/wiki/Embedded_SQL) **FAQ** [Frequently Asked Questions](https://en.wikipedia.org/wiki/FAQ) **FSM** [Free Space Map](storage-fsm.md) **GEQO** [Genetic Query Optimizer](geqo.md) **GIN** [Generalized Inverted Index](gin.md) **GiST** [Generalized Search Tree](gist.md) **Git** [Git](https://en.wikipedia.org/wiki/Git) **GMT** [Greenwich Mean Time](https://en.wikipedia.org/wiki/Greenwich_Mean_Time) **GSSAPI** [Generic Security Services Application Programming Interface](https://en.wikipedia.org/wiki/Generic_Security_Services_Application_Program_Interface) **GUC** [Grand Unified Configuration](config-setting.md), the PostgreSQL subsystem that handles server configuration **HBA** [Host-Based Authentication](auth-pg-hba-conf.md) **HOT** [Heap-Only Tuples](storage-hot.md) **IEC** [International Electrotechnical Commission](https://en.wikipedia.org/wiki/International_Electrotechnical_Commission) **IEEE** [Institute of Electrical and Electronics Engineers](https://standards.ieee.org/) **IPC** [Inter-Process Communication](https://en.wikipedia.org/wiki/Inter-process_communication) **I/O** [Input/Output](glossary.md#glossary-io) **ISO** [International Organization for Standardization](https://www.iso.org/home.html) **ISSN** [International Standard Serial Number](https://en.wikipedia.org/wiki/ISSN) **JDBC** [Java Database Connectivity](https://en.wikipedia.org/wiki/Java_Database_Connectivity) **JIT** [Just-in-Time compilation](https://en.wikipedia.org/wiki/Just-in-time_compilation) **JSON** [JavaScript Object Notation](https://www.json.org) **LDAP** [Lightweight Directory Access Protocol](https://en.wikipedia.org/wiki/Lightweight_Directory_Access_Protocol) **LSN** **Log Sequence Number** **MCF** Most Common Frequency, that is the frequency associated with some Most Common Value **MCV** Most Common Value, one of the values appearing most often within a particular table column **MITM** [Man-in-the-middle attack](https://en.wikipedia.org/wiki/Man-in-the-middle_attack) **MSVC** [Microsoft Visual C](https://en.wikipedia.org/wiki/Microsoft_Visual_C%2B%2B) **MVCC** [Multi-Version Concurrency Control](mvcc.md) **NLS** [National Language Support](https://en.wikipedia.org/wiki/Internationalization_and_localization) **ODBC** [Open Database Connectivity](https://en.wikipedia.org/wiki/Open_Database_Connectivity) **OID** [Object Identifier](datatype-oid.md) **OLAP** [Online Analytical Processing](https://en.wikipedia.org/wiki/Online_analytical_processing) **OLTP** [Online Transaction Processing](https://en.wikipedia.org/wiki/Online_transaction_processing) **ORDBMS** [Object-Relational Database Management System](https://en.wikipedia.org/wiki/Object%E2%80%93relational_database) **PAM** [Pluggable Authentication Modules](https://en.wikipedia.org/wiki/Pluggable_authentication_module) **PGSQL** [PostgreSQL](index.md) **PGXS** [PostgreSQL Extension System](extend-pgxs.md) **PID** [Process Identifier](https://en.wikipedia.org/wiki/Process_identifier) **PITR** [Point-In-Time Recovery](continuous-archiving.md) (Continuous Archiving) **PL** [Procedural Languages (server-side)](server-programming.md) **POSIX** [Portable Operating System Interface](https://en.wikipedia.org/wiki/POSIX) **RDBMS** [Relational Database Management System](https://en.wikipedia.org/wiki/Relational_database#RDBMS) **RFC** [Request For Comments](https://en.wikipedia.org/wiki/Request_for_Comments) **SGML** [Standard Generalized Markup Language](https://en.wikipedia.org/wiki/Standard_Generalized_Markup_Language) **SNI** [Server Name Indication](https://en.wikipedia.org/wiki/Server_Name_Indication), [RFC 6066](https://datatracker.ietf.org/doc/html/rfc6066#section-3) **SPI** [Server Programming Interface](spi.md) **SP-GiST** [Space-Partitioned Generalized Search Tree](spgist.md) **SQL** [Structured Query Language](https://en.wikipedia.org/wiki/SQL) **SRF** [Set-Returning Function](xfunc-c.md#xfunc-c-return-set) **SSH** [Secure Shell](https://en.wikipedia.org/wiki/Secure_Shell) **SSL** [Secure Sockets Layer](https://en.wikipedia.org/wiki/Transport_Layer_Security#SSL_1.0,_2.0,_and_3.0) **SSPI** [Security Support Provider Interface](https://msdn.microsoft.com/en-us/library/aa380493%28VS.85%29.aspx) **SYSV** [Unix System V](https://en.wikipedia.org/wiki/UNIX_System_V) **TCP/IP** [Transmission Control Protocol (TCP) / Internet Protocol (IP)](https://en.wikipedia.org/wiki/Transmission_Control_Protocol) **TID** [Tuple Identifier](datatype-oid.md) **TLS** [Transport Layer Security](https://en.wikipedia.org/wiki/Transport_Layer_Security) **TOAST** [The Oversized-Attribute Storage Technique](storage-toast.md) **TPC** [Transaction Processing Performance Council](http://www.tpc.org/) **URL** [Uniform Resource Locator](https://en.wikipedia.org/wiki/URL) **UTC** [Coordinated Universal Time](https://en.wikipedia.org/wiki/Coordinated_Universal_Time) **UTF** [Unicode Transformation Format](https://www.unicode.org/) **UTF8** [Eight-Bit Unicode Transformation Format](https://en.wikipedia.org/wiki/UTF-8) **UUID** [Universally Unique Identifier](datatype-uuid.md) **WAL** [Write-Ahead Log](wal.md) **XID** [Transaction Identifier](datatype-oid.md) **XML** [Extensible Markup Language](https://en.wikipedia.org/wiki/XML)