The pg_amop table stores information about operators associated with index access method operator classes. There is one row for each operator that is a member of an operator class.

Table 1. pg_catalog.pg_amop

column type references description
amopclaid oid pg_opclass.oid The index operator class this entry is for
amopsubtype oid pg_type.oid Subtype to distinguish multiple entries for one strategy; zero for default
amopstrategy smallint   Operator strategy number
amopreqcheck boolean   Index hit must be rechecked
amopopr oid pg_operator.oid OID of the operator