When should materialized views be updated?
Table of Contents
When should materialized views be updated?
The data in the materialized view remains unchanged, even when applications make changes to the data in the underlying tables. To update the data in a materialized view, you can use the REFRESH MATERIALIZED VIEW statement at any time.
How can you tell when a materialized view was last refreshed?
Question
- SELECT.
- OWNER,
- MVIEW_NAME,
- to_char(last_refresh_date, ‘yyyymmddhh24miss’) LAST_REFRESH_DATE.
- FROM all_mviews.
- WHERE owner = ‘MY_OWNER_NAME’
- AND mview_name = ‘MY_MATERIALIZED_VIEW_NAME’
Can we update MV in Oracle?
If the materialized view fails to revalidate, it cannot be refreshed or used for query rewrite. This clause lets you manage the staleness state of a materialized view after changes have been made to its master tables.
Can we update data in materialized view Oracle?
Primary key materialized views that contain a selected class of subqueries can still be incrementally (or fast) refreshed, if each master referenced has a materialized view log. A fast refresh uses materialized view logs to update only the rows that have changed since the last refresh.
Does materialized view improve performance?
A materialized view pre-computes, stores, and maintains its data in a dedicated SQL pool just like a table. There’s no recomputation needed each time a materialized view is used. That’s why queries that use all or a subset of the data in materialized views can get faster performance.
How do you update a query in materialized view?
Use the ALTER MATERIALIZED VIEW statement to modify an existing materialized view in one or more of the following ways:
- To change its storage characteristics.
- To change its refresh method, mode, or time.
- To alter its structure so that it is a different type of materialized view.
- To enable or disable query rewrite. Note:
