pg_collation
The catalog pg_collation describes the available collations, which are essentially mappings from an SQL name to operating system locale categories. See Section 23.2 for more information.
English manual coverage begins with PostgreSQL 7.4. Source history and runtime observations have their own recorded version boundaries.
Reading PG 18·Select a recorded version
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- metadata release
- 18.6
- runtime columns
- oid, collname, collnamespace, collowner, collprovider, collisdeterministic, collencoding, collcollate, collctype, colllocale, collicurules, collversion
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Definition PG 18
The catalog pg_collation describes the available collations, which are essentially mappings from an SQL name to operating system locale categories. See Section 23.2 for more information.
Catalog columns
| Column | Type | Nullability | Description |
|---|---|---|---|
| oid | oid | Not null | Row identifier |
| collname | name | Not null | Collation name (unique per namespace and encoding) |
| collnamespace | oid | Not null | The OID of the namespace that contains this collation |
| collowner | oid | Not null | Owner of the collation |
| collprovider | char | Not null | Provider of the collation: d = database default, b = builtin, c = libc, i = icu |
| collisdeterministic | bool | Not null | Is the collation deterministic? |
| collencoding | int4 | Not null | Encoding in which the collation is applicable, or -1 if it works for any encoding |
| collcollate | text | Nullable | LC_COLLATE for this collation object. If the provider is not libc, collcollate is NULL and colllocale is used instead. |
| collctype | text | Nullable | LC_CTYPE for this collation object. If the provider is not libc, collctype is NULL and colllocale is used instead. |
| colllocale | text | Nullable | Collation provider locale name for this collation object. If the provider is libc, colllocale is NULL; collcollate and collctype are used instead. |
| collicurules | text | Nullable | ICU collation rules for this collation object |
| collversion | text | Nullable | Provider-specific version of the collation. This is recorded when the collation is created and then checked when it is used, to detect changes in the collation definition that could lead to data corruption. |
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Source references
Full definition and evidence JSON
Definition sources
center · PostgreSQL 18 · catalog-bilingual-repair:89a25fe4fd84fa4da10a61a0c0a0422b0c82b194366a214d1b9d2b6f91b4f6c8
Text language: en · catalog-bilingual-repair:89a25fe4fd84fa4da10a61a0c0a0422b0c82b194366a214d1b9d2b6f91b4f6c8