ALTER VIEW

Changes properties 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 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 does not do anything you could not do by dropping and recreating the view. However, a superuser can alter ownership of any view.

Parameters

name

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

IF EXISTS

Do not throw an error if the view does not exist. Greenplum Database issues a notice 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 of 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 (string): 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 a Boolean value, such as true or false.

Notes

For historical reasons, ALTER TABLE can be used with views, too; however, the only variants of ALTER TABLE that are allowed with views are equivalent to the statements 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 Greenplum Database extension of the SQL standard.