How to fix the Oracle error ORA-01138: database must either be open in this instance or not at all?

In this post, you’ll learn more about the Oracle ErrorORA-01138: database must either be open in this instance or not at all with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-01138: database must either be open in this instance or not at all

Reason for the Error ORA-01138: database must either be open in this instance or not at all

The requested operation can not be done when the database is mounted but not open in this instance, and another instance has the database open.

How to fix the Error ORA-01138: database must either be open in this instance or not at all ?

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

Execute the operation in an open instance, open the datbase in this instance, or close the database in the other instances.