How to fix the Oracle error ORA-29921: Ancillary operator not supported with set view query block?

In this post, you’ll learn more about the Oracle ErrorORA-29921: Ancillary operator not supported with set view query block with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-29921: Ancillary operator not supported with set view query block

Reason for the Error ORA-29921: Ancillary operator not supported with set view query block

Outer view query block contains ancillary operator and view query block contains union all.

How to fix the Error ORA-29921: Ancillary operator not supported with set view query block ?

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

Define the union-all view query to contain the primary and ancillary query terms. i.e. have the operators within the view definition rather than in the query outside the view.