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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 |
|---|---|---|---|
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) | |
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 | pg_operator.oid | Negator of this operator, if any. | |
oprlsortop | oid | pg_operator.oid | If this operator supports merge joins, the operator that sorts the type of the left-hand operand (L<L). |
oprrsortop | oid | pg_operator.oid | If this operator supports merge joins, the operator that sorts the type of the right-hand operand (R<R). |
oprltcmpop | oid | pg_operator.oid | If this operator supports merge joins, the less-than operator that compares the left and right operand types (L<R). |
oprgtcmpop | oid | pg_operator.oid | If this operator supports merge joins, the greater-than operator that compares the left and right operand types (L>R). |
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. |
