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 |
---|---|---|---|
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. |