How to fix the Oracle error QSM-02178: MV has a view with UNION ALL that is not fast refreshable?

In this post, you’ll learn more about the Oracle ErrorQSM-02178: MV has a view with UNION ALL that is not fast refreshable with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

QSM-02178: MV has a view with UNION ALL that is not fast refreshable

Reason for the Error QSM-02178: MV has a view with UNION ALL that is not fast refreshable

The materialized view has a view whose definition involves a UNION ALL query that does not satisfy the requirements for fast refresh.

How to fix the Error QSM-02178: MV has a view with UNION ALL that is not fast refreshable ?

You can fix this error in Oracle by following the below steps

Check that the defining query of the view being referenced in the materialized view satisfies conditions for fast refresh of a UNION ALL materialized view.