55.36. `pg_opfamily`
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## 55.36. `pg_opfamily`

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 40.16.

Table 55.36. `pg_opfamily` Columns

Column Type Description
`oid` `oid` Row identifier
`opfmethod` `oid` (references `pg_am`.`oid`) Index access method operator family is for
`opfname` `name` Name of this operator family
`opfnamespace` `oid` (references `pg_namespace`.`oid`) Namespace of this operator family
`opfowner` `oid` (references `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`.

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