Oracle Error Message
QSM-02177: MV with UNION ALL in a view must match the view’s SELECT list
Reason for the Error
If a materialized view has a view whose definition involves a UNION ALL query, then the materialized view’s select list must match the underlying view’s select list exactly. It must not have any expressions and must not have add/drop/reorder columns from the underlying view.
Use select * when defining a materialized view with a UNION ALL in a view.