ALTER OPERATOR
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## ALTER OPERATOR

ALTER OPERATOR — change the definition of an operator

## Synopsis

    ALTER OPERATOR name ( { left_type | NONE } , right_type )
        OWNER TO { new_owner | CURRENT_ROLE | CURRENT_USER | SESSION_USER }

    ALTER OPERATOR name ( { left_type | NONE } , right_type )
        SET SCHEMA new_schema

    ALTER OPERATOR name ( { 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 `NONE` if 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.

## See Also

CREATE OPERATOR, DROP OPERATOR

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