How to fix the Oracle error QSM-02171: the materialized view has a join operation in the outer UNION block?

In this post, you’ll learn more about the Oracle ErrorQSM-02171: the materialized view has a join operation in the outer UNION block with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

QSM-02171: the materialized view has a join operation in the outer UNION block

Reason for the Error QSM-02171: the materialized view has a join operation in the outer UNION block

Fast refresh is not supported if a materialized view having the UNION operator contains a join operation.

How to fix the Error QSM-02171: the materialized view has a join operation in the outer UNION block ?

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

Rewrite the materialized view query without the join.