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.
||oid||pg_opclass.oid||The index operator class this entry is for|
||oid||pg_type.oid||Subtype to distinguish multiple entries for one strategy; zero for default|
||smallint||Operator strategy number|
||boolean||Index hit must be rechecked|
||oid||pg_operator.oid||OID of the operator|