Understanding and Resolving ORA-01113: File Needs Media Recovery in Oracle

TL;DR: The ORA-01113 error occurs when a data file requires media recovery before it can be accessed. This issue often arises during database startup or when attempting to bring an offline tablespace back online. In this article, we explain the causes of this error and provide step-by-step instructions to resolve it effectively.

Introduction

The ORA-01113 error in Oracle Database indicates that a specific data file requires media recovery. This error can appear during database startup or when managing tablespaces, such as attempting to bring an offline tablespace back online. Understanding the root causes and resolution steps is essential to restore database functionality promptly.

What Causes ORA-01113?

The ORA-01113 error can occur for various reasons, including:

An interrupted recovery process left a data file in an inconsistent state.
Uncommitted transactions or redo information need to be applied to the data file.
A tablespace taken offline without clean checkpoints.
Unexpected system or database crashes.

Recognizing the ORA-01113 Error

When attempting to access or bring a tablespace online, you may encounter the following error message:

SQL> ALTER TABLESPACE sample ONLINE;
ERROR at line 1:
ORA-01113: file 27 needs media recovery
ORA-01110: data file 27: '/u02/oracle/oradata/ORCL/sample.dbf'

This error indicates that the specified data file requires recovery. The accompanying ORA-01110 error specifies the file name and path.

How to Resolve ORA-01113

Follow these steps to resolve the error and restore the affected tablespace:

Identify the file that requires recovery:
```
SQL> SELECT * FROM v$recover_file;
```
This query lists files that need recovery, along with their file IDs.
Perform media recovery on the affected file:
```
SQL> RECOVER DATAFILE '/u02/oracle/oradata/ORCL/sample.dbf';
```
The recovery process applies necessary redo logs to bring the file to a consistent state.
Bring the tablespace online:
```
SQL> ALTER TABLESPACE sample ONLINE;
```

Example Scenario

Consider the following series of actions and resolutions:

SQL> ALTER TABLESPACE sample ONLINE;
ORA-01113: file 27 needs media recovery
ORA-01110: data file 27: '/u02/oracle/oradata/ORCL/sample.dbf'

SQL> RECOVER DATAFILE '/u02/oracle/oradata/ORCL/sample.dbf';
Media recovery complete.

SQL> ALTER TABLESPACE sample ONLINE;
ORA-01113: file 29 needs media recovery
ORA-01110: data file 29: '/u02/oracle/oradata/ORCL/SAMPLE10.dbf'

SQL> RECOVER DATAFILE '/u02/oracle/oradata/ORCL/SAMPLE10.dbf';
Media recovery complete.

SQL> ALTER TABLESPACE sample ONLINE;
Tablespace altered.

Best Practices to Prevent ORA-01113

Ensure regular database backups to minimize recovery needs.
Monitor tablespace and data file statuses using views like v$datafile and v$tablespace.
Configure redo logs and archive log settings appropriately to support recovery.
Perform clean shutdowns to avoid leaving files in an inconsistent state.

Conclusion

The ORA-01113 error is a common issue in Oracle databases when data files require media recovery. By understanding the causes and following the outlined steps, you can quickly resolve the error and restore database operations. Regular monitoring and adhering to best practices can help prevent similar issues in the future.