How to Diagnose and Fix the ORA-01181 Error in Oracle

If you encounter the ORA-01181 error in Oracle, it means that a file has been added to the database, but it is not accessible. This can happen due to various reasons such as the file being offline, missing, or corrupted. In this blog post, we will discuss how to diagnose and fix this error.

Diagnosing the ORA-01181 Error

When you encounter the ORA-01181 error, the first step is to identify the cause of the issue. You can start by checking the alert log for any additional information about the error. Additionally, you can use the following query to check the status of the data files in the database:

SELECT file#, status, name FROM v$datafile;

This query will show you the status of each data file in the database, and you can identify if any of them are offline or in need of recovery.

Fixing the ORA-01181 Error

Once you have identified the cause of the ORA-01181 error, you can take the appropriate steps to fix it. Here are some common scenarios and their respective solutions:

Scenario 1: Data File is Offline

If the data file is offline, you can bring it back online using the following command:

ALTER DATABASE DATAFILE '<file_path>' ONLINE;

Replace ‘

ALTER DATABASE CREATE DATAFILE '</file_path><file_path>';