How to fix the Oracle error ORA-12856: cannot run parallel query on a loopback connection?

In this post, you’ll learn more about the Oracle ErrorORA-12856: cannot run parallel query on a loopback connection with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-12856: cannot run parallel query on a loopback connection

Reason for the Error ORA-12856: cannot run parallel query on a loopback connection

A table or index in a parallel query is referenced via a loopback connection.

How to fix the Error ORA-12856: cannot run parallel query on a loopback connection ?

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

Do not use loopback connection when running a query in parallel.