pg_operator

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.

Table 1. pg_catalog.pg_operator

column	type	references	description
oid	oid		Row identifier (hidden attribute, must be explicityly selected)
oprname	name		Name of the operator
oprnamespace	oid	pg_namespace.oid	The OID of the namespace that contains this operator
oprowner	oid	pg_authid.oid	Owner of the operator
oprkind	char		b = infix (both), l = prefix (left), r = postfix (right)
koprcanmerge	boolean		This operator supports merge joins
oprcanhash	boolean		This operator supports hash joins
oprleft	oid	pg_type.oid	Type of the left operand
oprright	oid	pg_type.oid	Type of the right operand
oprresult	oid	pg_type.oid	Type of the result
oprcom	oid	pg_operator.oid	Commutator of this operator, if any
oprnegate	oid	pg_operator.oid	Negator of this operator, if any
oprcode	regproc	pg_proc.oid	Function that implements this operator
oprrest	regproc	pg_proc.oid	Restriction selectivity estimation function for this operator
oprjoin	regproc	pg_proc.oid	Join selectivity estimation function for this operator