How to fix the Oracle error QSM-02170: tables must be identical across the UNION operator?

In this post, you’ll learn more about the Oracle ErrorQSM-02170: tables must be identical across the UNION operator with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

QSM-02170: tables must be identical across the UNION operator

Reason for the Error QSM-02170: tables must be identical across the UNION operator

You have specified a materialized view using the UNION operator and the tables on each side of the UNION operator do not match. Fast refresh is not supported in this context.

How to fix the Error QSM-02170: tables must be identical across the UNION operator ?

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

Restructure the materialized view query such that the respective sides of the UNION operator have the same table.