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 51.35. 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.