ALTER VIEW
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## ALTER VIEW

ALTER VIEW — change the definition of a view

## Synopsis

    ALTER VIEW [ IF EXISTS ] name ALTER [ COLUMN ] column_name SET DEFAULT expression
    ALTER VIEW [ IF EXISTS ] name ALTER [ COLUMN ] column_name DROP DEFAULT
    ALTER VIEW [ IF EXISTS ] name OWNER TO { new_owner | CURRENT_USER | SESSION_USER }
    ALTER VIEW [ IF EXISTS ] name RENAME [ COLUMN ] column_name TO new_column_name
    ALTER VIEW [ IF EXISTS ] name RENAME TO new_name
    ALTER VIEW [ IF EXISTS ] name SET SCHEMA new_schema
    ALTER VIEW [ IF EXISTS ] name SET ( view_option_name [= view_option_value] [, ... ] )
    ALTER VIEW [ IF EXISTS ] name RESET ( view_option_name [, ... ] )

## Description

`ALTER VIEW` changes various auxiliary properties of a view. (If you want to modify the view's defining query, use `CREATE OR REPLACE VIEW`.)

You must own the view to use `ALTER VIEW`. To change a view's schema, you must also have `CREATE` privilege on the new schema. To alter the owner, you must also be a direct or indirect member of the new owning role, and that role must have `CREATE` privilege on the view's schema. (These restrictions enforce that altering the owner doesn't do anything you couldn't do by dropping and recreating the view. However, a superuser can alter ownership of any view anyway.)

## Parameters

`name`

  The name (optionally schema-qualified) of an existing view.

`column_name`

  Name of an existing column.

`new_column_name`

  New name for an existing column.

`IF EXISTS`

  Do not throw an error if the view does not exist. A notice is issued in this case.

`SET`/`DROP DEFAULT`

  These forms set or remove the default value for a column. A view column's default value is substituted into any `INSERT` or `UPDATE` command whose target is the view, before applying any rules or triggers for the view. The view's default will therefore take precedence over any default values from underlying relations.

`new_owner`

  The user name of the new owner of the view.

`new_name`

  The new name for the view.

`new_schema`

  The new schema for the view.

`SET ( `view_option_name` [= `view_option_value`] [, ... ] )`
`RESET ( `view_option_name` [, ... ] )`

  Sets or resets a view option. Currently supported options are:

  `check_option` (`enum`)

    Changes the check option of the view. The value must be `local` or `cascaded`.

  `security_barrier` (`boolean`)

    Changes the security-barrier property of the view. The value must be Boolean value, such as `true` or `false`.

## Notes

For historical reasons, `ALTER TABLE` can be used with views too; but the only variants of `ALTER TABLE` that are allowed with views are equivalent to the ones shown above.

## Examples

To rename the view `foo` to `bar`:

    ALTER VIEW foo RENAME TO bar;

To attach a default column value to an updatable view:

    CREATE TABLE base_table (id int, ts timestamptz);
    CREATE VIEW a_view AS SELECT * FROM base_table;
    ALTER VIEW a_view ALTER COLUMN ts SET DEFAULT now();
    INSERT INTO base_table(id) VALUES(1);  -- ts will receive a NULL
    INSERT INTO a_view(id) VALUES(2);  -- ts will receive the current time

## Compatibility

`ALTER VIEW` is a PostgreSQL extension of the SQL standard.

## See Also

CREATE VIEW, DROP VIEW

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