How to diagnose and fix the ORA-00263 READ COMMITTED error in Oracle

If you encounter the ORA-00263 READ COMMITTED error in Oracle, it indicates that there is a problem with the read consistency in the database. This error can occur due to various reasons such as incorrect configuration, insufficient permissions, or corrupt data files. In this article, we will discuss how to diagnose and fix this error to ensure the smooth operation of your Oracle database.

Diagnosing the ORA-00263 error

When you encounter the ORA-00263 error, the first step is to identify the root cause of the issue. Here are some steps to diagnose the error:

1. Check the alert log: The Oracle alert log is a valuable source of information for diagnosing errors. Look for any relevant error messages or warnings that may provide insight into the cause of the ORA-00263 error.

2. Review the database configuration: Verify the database configuration settings, including the isolation level and transaction settings. Ensure that the READ COMMITTED isolation level is correctly configured.

3. Check for corrupt data files: Use the DBVERIFY utility to check for any corrupt data files that may be causing the error. If any corrupt files are found, take appropriate action to repair or replace them.

Fixing the ORA-00263 error

Once you have diagnosed the ORA-00263 error, you can take the necessary steps to fix it. Here are some potential solutions:

1. Adjust the isolation level: If the error is related to the READ COMMITTED isolation level, you may need to adjust the database configuration to ensure that it is set correctly. You can do this using the ALTER SESSION or ALTER SYSTEM commands.

2. Grant appropriate permissions: Ensure that the user or application experiencing the error has the necessary permissions to access the database objects and perform the required operations. Use the GRANT command to grant the required privileges.

3. Rebuild indexes: If the error is related to data consistency issues, consider rebuilding the affected indexes using the REBUILD option of the ALTER INDEX command.

4. Consult Oracle documentation: If you are unable to resolve the error using the above steps, consult the Oracle documentation or seek assistance from Oracle support. The Oracle documentation provides detailed information on error codes and their potential causes and solutions.

Sample code

Here is an example of how to adjust the isolation level using the ALTER SESSION command:


And here is an example of granting permissions using the GRANT command:


In conclusion, the ORA-00263 READ COMMITTED error in Oracle can be diagnosed and fixed by carefully reviewing the database configuration, adjusting isolation levels, granting appropriate permissions, and consulting Oracle documentation. By following the steps outlined in this article, you can effectively resolve the error and ensure the smooth operation of your Oracle database.

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