---
title: "pg_range"
id: catalog-pg-range
pg_version: "20devel"
---

<a id="catalog-pg-range"></a>

## 52.48. pg_range

The catalog pg_range stores information about range types. This is in addition to the types' entries in [pg_type](catalog-pg-type.md). 

**pg_range Columns**

| Column Type | Description | 
| --- | --- |
| `rngtypid` `oid` (references [pg_type](catalog-pg-type.md).`oid`) | OID of the range type |
| `rngsubtype` `oid` (references [pg_type](catalog-pg-type.md).`oid`) | OID of the element type (subtype) of this range type |
| `rngmultitypid` `oid` (references [pg_type](catalog-pg-type.md).`oid`) | OID of the multirange type for this range type |
| `rngcollation` `oid` (references [pg_collation](catalog-pg-collation.md).`oid`) | OID of the collation used for range comparisons, or zero if none |
| `rngsubopc` `oid` (references [pg_opclass](catalog-pg-opclass.md).`oid`) | OID of the subtype's operator class used for range comparisons |
| `rngconstruct2` `regproc` (references [pg_proc](catalog-pg-proc.md).`oid`) | OID of the 2-argument range constructor function (lower and upper) |
| `rngconstruct3` `regproc` (references [pg_proc](catalog-pg-proc.md).`oid`) | OID of the 3-argument range constructor function (lower, upper, and flags) |
| `rngmltconstruct0` `regproc` (references [pg_proc](catalog-pg-proc.md).`oid`) | OID of the 0-argument multirange constructor function (constructs empty range) |
| `rngmltconstruct1` `regproc` (references [pg_proc](catalog-pg-proc.md).`oid`) | OID of the 1-argument multirange constructor function (constructs multirange from single range, also used as cast function) |
| `rngmltconstruct2` `regproc` (references [pg_proc](catalog-pg-proc.md).`oid`) | OID of the 2-argument multirange constructor function (constructs multirange from array of ranges) |
| `rngcanonical` `regproc` (references [pg_proc](catalog-pg-proc.md).`oid`) | OID of the function to convert a range value into canonical form, or zero if none |
| `rngsubdiff` `regproc` (references [pg_proc](catalog-pg-proc.md).`oid`) | OID of the function to return the difference between two element values as `double precision`, or zero if none |

`rngsubopc` (plus `rngcollation`, if the element type is collatable) determines the sort ordering used by the range type. `rngcanonical` is used when the element type is discrete. `rngsubdiff` is optional but should be supplied to improve performance of GiST indexes on the range type.