pg_amop

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.

An entry’s amopmethod must match the opfmethod of its containing operator family (including amopmethod here is an intentional denormalization of the catalog structure for performance reasons). Also, amoplefttype and amoprighttype must match the oprleft and oprright fields of the referenced pg_operator entry.

Table 1. pg_catalog.pg_amop

column	type	references	description
oid	oid		Row identifier (hidden attribute; must be explicitly selected)
amopfamily	oid	pg_opfamily.oid	The operator family that this entry is for
amoplefttype	oid	pg_type.oid	Left-hand input data type of operator
amoprighttype	oid	pg_type.oid	Right-hand input data type of operator
amopstrategy	smallint		Operator strategy number
amoppurpose	char		Operator purpose, either s for search or o for ordering
amopopr	oid	pg_operator.oid	OID of the operator
amopmethod	oid	pg_am.oid	Index access method for the operator family
amopsortfamily	oid	pg_opfamily.oid	If an ordering operator, the B-tree operator family that this entry sorts according to; zero if a search operator