How to fix the Oracle error QSM-02040: top level query contains GSets and the key is too long for rewrite?

In this post, you’ll learn more about the Oracle ErrorQSM-02040: top level query contains GSets and the key is too long for rewrite with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

QSM-02040: top level query contains GSets and the key is too long for rewrite

Reason for the Error QSM-02040: top level query contains GSets and the key is too long for rewrite

The capability in question is not supported when the materialized view uses a grouping set with too many keys.

How to fix the Error QSM-02040: top level query contains GSets and the key is too long for rewrite ?

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

Reduce the number of grouping set keys.