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Note: The following description applies both to Postgres-XC and PostgreSQL if not described explicitly.
The catalog pg_opfamily defines operator families. Each operator family is a collection of operators and associated support routines that implement the semantics specified for a particular index access method. Furthermore, the operators in a family are all "compatible", in a way that is specified by the access method. The operator family concept allows cross-data-type operators to be used with indexes and to be reasoned about using knowledge of access method semantics.
Operator families are described at length in Section 34.14.
Table 45-33. pg_opfamily Columns
| Name | Type | References | Description |
|---|---|---|---|
| opfmethod | oid | pg_am.oid | Index access method operator family is for |
| opfname | name | Name of this operator family | |
| opfnamespace | oid | pg_namespace.oid | Namespace of this operator family |
| opfowner | oid | pg_authid.oid | Owner of the operator family |
The majority of the information defining an operator family is not in its pg_opfamily row, but in the associated rows in pg_amop, pg_amproc, and pg_opclass.