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What is the use of materialized view in Oracle?

What is the use of materialized view in Oracle?

Oracle uses materialized views (also known as snapshots in prior releases) to replicate data to non-master sites in a replication environment and to cache expensive queries in a data warehouse environment.

What is the difference between materialized view and view?

The basic difference between View and Materialized View is that Views are not stored physically on the disk. However, Materialized View is a physical copy, picture or snapshot of the base table. A view is always updated as the query creating View executes each time the View is used.

What is a materialized view and when would it be used?

Views are generally used when data is to be accessed infrequently and data in table get updated on frequent basis. On other hand Materialized Views are used when data is to be accessed frequently and data in table not get updated on frequent basis.

How does Oracle materialized view work?

A materialized view in Oracle is a database object that contains the results of a query. They are local copies of data located remotely, or are used to create summary tables based on aggregations of a table’s data. Materialized views, which store data based on remote tables are also, know as snapshots.

Can we insert data into materialized view?

You can’t insert data into a materialized view as you can with a table. To update the contents of a materialized view, you can execute a query to refresh it. This will re-execute the query used to create it.

Why do we need to refresh materialized views in Oracle?

If any of the materialized views are defined as ON DEMAND refresh (irrespective of whether the refresh method is FAST, FORCE, or COMPLETE), you must refresh them in the correct order (taking into account the dependencies between the materialized views) because the nested materialized view are refreshed with respect to the current contents of the other materialized views (whether fresh or not).

When to use a materialized view?

Materialized views are primarily used to increase application performance when it isn’t feasible or desirable to use a standard view with indexes applied to it. Materialized views can be updated on a regular basis either through triggers or by using the ON COMMIT REFRESH option.

Is materialized view refreshed automatically?

A materialized view can be refreshed automatically using the ON COMMIT method. Therefore, whenever a transaction commits which has updated the tables on which a materialized view is defined, those changes are automatically reflected in the materialized view.

What is Oracle material view?

A materialized view in Oracle is a database object that contains the results of a query. It stores data physically and get updated periodically.

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