ALTER VIEW
Function
ALTER VIEW modifies all auxiliary attributes of a view. (To modify the query definition of a view, use CREATE OR REPLACE VIEW.)
Precautions
- Only the view owner can modify a view by running ALTER VIEW.
- To change a view's schema, you must also have the CREATE permission 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.
- An administrator can change the owner relationship of any view.
Syntax
- Set the default value of the view column.
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ALTER VIEW [ IF EXISTS ] view_name ALTER [ COLUMN ] column_name SET DEFAULT expression;
- Remove the default value of the view column.
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ALTER VIEW [ IF EXISTS ] view_name ALTER [ COLUMN ] column_name DROP DEFAULT;
- Change the owner of a view.
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ALTER VIEW [ IF EXISTS ] view_name OWNER TO new_owner;
- Rename a view.
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ALTER VIEW [ IF EXISTS ] view_name RENAME TO new_name;
- Set the schema of the view.
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ALTER VIEW [ IF EXISTS ] view_name SET SCHEMA new_schema;
- Set the options of the view.
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ALTER VIEW [ IF EXISTS ] view_name SET ( { view_option_name [ = view_option_value ] } [, ... ] );
- Reset the options of the view.
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ALTER VIEW [ IF EXISTS ] view_name RESET ( view_option_name [, ... ] );
- Rebuild the current view and its lower-layer and upper-layer dependent views.
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ALTER VIEW [ IF EXISTS ] view_name REBUILD;
- Rebuild the current view and its lower-layer dependent views.
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ALTER VIEW [ IF EXISTS ] ONLY view_name REBUILD;
Parameter Description
- IF EXISTS
If this option is specified, no error is reported if the view does not exist. Only a message is displayed.
- view_name
Specifies the view name, which can be schema-qualified.
Value range: a string. It must comply with the naming convention.
- column_name
Indicates an optional list of names to be used for columns of the view. If not given, the column names are deduced from the query.
Value range: a string. It must comply with the naming convention.
- SET/DROP DEFAULT
Sets or deletes the default value of a column. Currently, this parameter does not take effect.
- new_owner
Specifies the new owner of a view.
- new_name
Specifies the new view name.
- new_schema
Specifies the new schema of the view.
- view_option_name [ = view_option_value ]
This clause specifies optional parameters for a view.
Currently, the only parameter supported by view_option_name is security_barrier, which should be enabled when a view is intended to provide row-level security.
Value range: boolean type. It can be TRUE or FALSE.
- REBUILD
This clause is used for view decoupling. You can use the saved original statement to rebuild views and restore the dependencies. Note the following:
- View rebuilding starts from the current view and updates all associated backward views. If the forward views on which the current view depends are also unavailable, automatic rebuilding is triggered.
- The temporary tables and views that have dependency relationships cannot be decoupled and dropped. However, you can perform the REBUILD operation on temporary views that do not have dependency relationships.
- View schema names and view names can be modified. The names of rebuilt view schemas or views are re-created based on the latest name, but the query operation retains the original definition.
- Only fields of the character, number, and time types in the base table can be modified. When a field is added to the base table, the view is not invalidated and the definition remains unchanged.
- Invalid views are exported as comments during backup. You need to manually restore the invalid views.
- Views can be automatically rebuilt when VIEW_INDEPENDENT is set to on.
The upper-layer cascading views become invalid in the following scenarios:
- DROP TABLE/VIEW
- RENAME TABLE/VIEW
- ALTER TABLE DROP COLUMN
- ALTER TABLE CHANGE/ALTER COLUMN TYPE
- ALTER TABLE CHANGE/ALTER COLUMN NAME
- ALTER TABLE/VIEW NAMESPACE
- ALTER TABLE/VIEW RENAME
- ONLY
Only views and their dependent views are rebuilt. This function is available only if view_independent is set to on.
Examples
Create an example view myview:
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CREATE OR REPLACE VIEW myview AS SELECT * FROM pg_tablespace WHERE spcname = 'pg_default'; |
Rename a view.
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ALTER VIEW myview RENAME TO product_view; |
Change the schema of a view.
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ALTER VIEW product_view SET schema public; |
Recreate a view (GUC parameter view_independent should be set to on).
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ALTER VIEW public.product_view REBUILD; |
Rebuild the dependency view (GUC parameter view_independent should be set to on).
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ALTER VIEW ONLY public.product_view REBUILD; |
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