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.

    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 int2 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

    Parent topic: System Catalogs Definitions