The pg_operator system catalog table stores information about operators, both built-in and those defined by CREATE OPERATOR. Unused column contain zeroes. For example, oprleft is zero for a prefix operator.

    columntypereferencesdescription
    oidoid Row identifier (hidden attribute, must be explicityly selected)
    oprnamename Name of the operator
    oprnamespaceoidpg_namespace.oidThe OID of the namespace that contains this operator
    oprowneroidpg_authid.oidOwner of the operator
    oprkindchar b = infix (both), l = prefix (left), r = postfix (right)
    oprcanmergeboolean This operator supports merge joins
    oprcanhashboolean This operator supports hash joins
    oprleftoidpg_type.oidType of the left operand
    oprrightoidpg_type.oidType of the right operand
    oprresultoidpg_type.oidType of the result
    oprcomoidpg_operator.oidCommutator of this operator, if any
    oprnegateoidpg_operator.oidNegator of this operator, if any
    oprcoderegprocpg_proc.oidFunction that implements this operator
    oprrestregprocpg_proc.oidRestriction selectivity estimation function for this operator
    oprjoinregprocpg_proc.oidJoin selectivity estimation function for this operator

    Parent topic: System Catalogs Definitions