How to fix the Oracle error ORA-16001: database already open for read-only access by another instance?

In this post, you’ll learn more about the Oracle ErrorORA-16001: database already open for read-only access by another instance with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-16001: database already open for read-only access by another instance

Reason for the Error ORA-16001: database already open for read-only access by another instance

The database has been opened for read-only access by another instance, and cannot be opened for read/write access by this instance.

How to fix the Error ORA-16001: database already open for read-only access by another instance ?

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

This instance must be opened for read/write access, or all other instances must first be shut down and reopened for read-only access.