How to fix the Oracle error ORA-01530: a database already mounted by the instance?

In this post, you’ll learn more about the Oracle ErrorORA-01530: a database already mounted by the instance with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-01530: a database already mounted by the instance

Reason for the Error ORA-01530: a database already mounted by the instance

During ALTER DATABASE MOUNT, an attempt is being made to mount a database on an instance in which a database is or has previously been mounted.

How to fix the Error ORA-01530: a database already mounted by the instance ?

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

If you wish to mount the database, shutdown the instance and then startup the instance and retry the operation.