## 52.35. `pg_opfamily`

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 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 38.16](xindex.html).

**Table 52.35. `pg_opfamily` Columns**

|                                               Column Type<br/><br/> Description                                               |
|-------------------------------------------------------------------------------------------------------------------------------|
|                                             `oid` `oid`<br/><br/> Row identifier                                              |
|    `opfmethod` `oid` (references [`pg_am`](catalog-pg-am.html).`oid`)<br/><br/> Index access method operator family is for    |
|                                    `opfname` `name`<br/><br/> Name of this operator family                                    |
|`opfnamespace` `oid` (references [`pg_namespace`](catalog-pg-namespace.html).`oid`)<br/><br/> Namespace of this operator family|
|       `opfowner` `oid` (references [`pg_authid`](catalog-pg-authid.html).`oid`)<br/><br/> 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`](catalog-pg-amop.html), [`pg_amproc`](catalog-pg-amproc.html), and [`pg_opclass`](catalog-pg-opclass.html).

