Postgresql view auto update

If an automatically updatable view contains a WHERE condition, the condition restricts which rows of the base relation are available to be modified by UPDATE and DELETE statements on the view. However, an UPDATE is allowed to change a row so that it no longer satisfies the WHERE condition, and thus is no longer visible through the view. You can get the effect of an updatable view by creating rules that rewrite inserts, etc. Updating a row with a trigger.

In case you have a WHERE condition in the defining query of a view , you still can update or delete the rows that are not visible through the view.

REFRESH MATERIALIZED VIEW completely replaces the contents of a materialized view. To execute this command you must be the owner of the materialized view. This option has to do with updatable views. If they do not, the update will be rejected.

Check for integrity on this view. CASCADED is assumed if neither CASCADED nor LOCAL is specified. This feature has been introduced by this commit and is called auto -updatable views.

I create them manually, but 'set options' doesn't work. INSERT, UPDATE or DELETE on views. I created a materialized view named view _table_A on a foreign data wrapper table table_A. PostgreSQL has introduced automatically updatable views in 9. What I want is for the view to be automatically updated after every new insert in table_A. Is it possible to refresh a materialized view automatically without using triggers?

The entire materialized view is recalculated when using concurrently. Then postgres will use the unique index on the materialized view to find which rows have changed and only update those rows from the recalculated values. This prevents blocking of the entire view, but it does not speed up calculation time. You can query against the materialized view while it is being updated.

You can use WHERE clause with UPDATE query to update the selected rows. Otherwise, all the rows would be updated. You need some kind of scheduler that runs refresh materialized view e. Alternatively, if you need a MATERIALIZED VIEW that refreshes when you run SELECT, just remove MATERIALIZED and use a regular VIEW.

How should I go about doing this? Many ways to achieve this.

This project aims to implement SQL92-compatible updatable views. Currently there is a prototype which implements single-relation views with local and cascaded check option via the present rule rewrite system. A view is named query that provides another way to present data in the database tables.

A view is defined based on one or more tables, which are known as base tables. When you create a view , you basically create a query and assign it a name, therefore a view is useful for wrapping a commonly used complex query. The SQL UPDATE VIEW command can be used to modify the data of a view.

All views are not updatable. So, UPDATE command is not applicable to all views. An updatable view is one which allows performing a UPDATE command on itself without affecting any other table.