ALTER OPERATOR
ALTER OPERATOR
ALTER OPERATOR - change the definition of an operator
Synopsis
ALTER OPERATORname( {left_type| NONE } ,right_type) OWNER TO {new_owner| CURRENT_ROLE | CURRENT_USER | SESSION_USER } ALTER OPERATORname( {left_type| NONE } ,right_type) SET SCHEMAnew_schemaALTER OPERATORname( {left_type| NONE } ,right_type) SET ( { RESTRICT = {res_proc| NONE } | JOIN = {join_proc| NONE } | COMMUTATOR =com_op| NEGATOR =neg_op| HASHES | MERGES } [, ... ] )
Description
ALTER OPERATOR
changes the definition of
an operator.
You must own the operator to use
ALTER OPERATOR
.
To alter the owner, you must be able to
SET ROLE
to the
new owning role, and that role must have
CREATE
privilege on the operator's schema.
(These restrictions enforce that altering the owner
doesn't do anything you couldn't do by dropping and recreating the operator.
However, a superuser can alter ownership of any operator anyway.)
Parameters
-
name -
The name (optionally schema-qualified) of an existing operator.
-
left_type -
The data type of the operator's left operand; write
NONEif the operator has no left operand. -
right_type -
The data type of the operator's right operand.
-
new_owner -
The new owner of the operator.
-
new_schema -
The new schema for the operator.
-
res_proc -
The restriction selectivity estimator function for this operator; write NONE to remove existing selectivity estimator.
-
join_proc -
The join selectivity estimator function for this operator; write NONE to remove existing selectivity estimator.
-
com_op -
The commutator of this operator. Can only be changed if the operator does not have an existing commutator.
-
neg_op -
The negator of this operator. Can only be changed if the operator does not have an existing negator.
-
HASHES -
Indicates this operator can support a hash join. Can only be enabled and not disabled.
-
MERGES -
Indicates this operator can support a merge join. Can only be enabled and not disabled.
Notes
Refer to Section 36.14 and Section 36.15 for further information.
Since commutators come in pairs that are commutators of each other,
ALTER OPERATOR SET COMMUTATOR
will also set the
commutator of the
com_op
to be the target operator. Likewise,
ALTER OPERATOR SET
NEGATOR
will also set the negator of
the
neg_op
to be the
target operator. Therefore, you must own the commutator or negator
operator as well as the target operator.
Examples
Change the owner of a custom operator
a @@ b
for type
text
:
ALTER OPERATOR @@ (text, text) OWNER TO joe;
Change the restriction and join selectivity estimator functions of a
custom operator
a && b
for
type
int[]
:
ALTER OPERATOR && (int[], int[]) SET (RESTRICT = _int_contsel, JOIN = _int_contjoinsel);
Mark the
&&
operator as being its own
commutator:
ALTER OPERATOR && (int[], int[]) SET (COMMUTATOR = &&);
Compatibility
There is no
ALTER OPERATOR
statement in
the SQL standard.