> For the complete documentation index, see [llms.txt](https://docs.postgresql.tw/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.postgresql.tw/15/internals/system-catalogs/pg_range.md).

# 53.43. pg\_range

## 53.43. pg\_range

The catalog `pg_range` stores information about range types. This is in addition to the types' entries in [`pg_type`](/15/internals/system-catalogs/pg_type.md).

**Table 53.43. `pg_range` Columns**

| <p>Column Type</p><p>Description</p>                                                                                                                                                                                                                                                           |
| ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| <p><code>rngtypid</code> <code>oid</code> (references <a href="/15/internals/system-catalogs/pg_type.md"><code>pg\_type</code></a>.<code>oid</code>)</p><p>OID of the range type</p>                                                                                                           |
| <p><code>rngsubtype</code> <code>oid</code> (references <a href="/15/internals/system-catalogs/pg_type.md"><code>pg\_type</code></a>.<code>oid</code>)</p><p>OID of the element type (subtype) of this range type</p>                                                                          |
| <p><code>rngmultitypid</code> <code>oid</code> (references <a href="/15/internals/system-catalogs/pg_type.md"><code>pg\_type</code></a>.<code>oid</code>)</p><p>OID of the multirange type for this range type</p>                                                                             |
| <p><code>rngcollation</code> <code>oid</code> (references <a href="/15/internals/system-catalogs/pg_collation.md"><code>pg\_collation</code></a>.<code>oid</code>)</p><p>OID of the collation used for range comparisons, or zero if none</p>                                                  |
| <p><code>rngsubopc</code> <code>oid</code> (references <a href="/15/internals/system-catalogs/pg_opclass.md"><code>pg\_opclass</code></a>.<code>oid</code>)</p><p>OID of the subtype's operator class used for range comparisons</p>                                                           |
| <p><code>rngcanonical</code> <code>regproc</code> (references <a href="/15/internals/system-catalogs/pg_proc.md"><code>pg\_proc</code></a>.<code>oid</code>)</p><p>OID of the function to convert a range value into canonical form, or zero if none</p>                                       |
| <p><code>rngsubdiff</code> <code>regproc</code> (references <a href="/15/internals/system-catalogs/pg_proc.md"><code>pg\_proc</code></a>.<code>oid</code>)</p><p>OID of the function to return the difference between two element values as <code>double precision</code>, or zero if none</p> |

`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.

***

原文：[PostgreSQL 15.19 Documentation](/15/internals/system-catalogs/pg_range.md)（英文原文，待翻譯）


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