52.35. 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 37.16.
Table 52.35. pg_opfamily Columns
Column Type Description  | 
|---|
 Row identifier  | 
 Index access method operator family is for  | 
 Name of this operator family  | 
 Namespace of this operator family  | 
 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.