pg_collation

The pg_collation catalog provides information about available collations.

Column name	Data type	Description
oid	oid	A row identifier.
collname	name	The collation name, unique per namespace and encoding.
collnamespace	oid (references pg_namespace.oid)	The OID of the namespace that contains the collation.
collowner	oid (references pg_authid.oid)	The OID of the collation owner.
collprovider	char	The provider of the collation. The possible values are: d – Database default. b – Built-in. c – libc. i – ICU.
collisdeterministic	bool	Specifies whether the collation is deterministic.
collencoding	int4	The encoding to which the collation is applicable. -1 – Applicable to any encoding.
collcollate	text	The LC_COLLATE value for the collation object. NULL – The provider is not libc. In this case, colllocale is used.
collctype	text	The LC_CTYPE value for the collation object. NULL – The provider is not libc. In this case, colllocale is used.
colllocale	text	The locale name used by the collation provider. NULL – The provider is libc. In this case, collcollate and collctype apply instead.
collicurules	text	The ICU collation rules for the collation object.
collversion	text	The collation’s provider-specific version. The value is stored when it is created and verified later to detect changes that might cause data corruption.