Introduction:
Oracle Database 12c offers a robust mechanism for handling backup and recovery tasks through its Flash Recovery Area (FRA). However, users may encounter issues like the ORA-19815 error, which indicates that the FRA is running out of space. In this article, we’ll delve into the causes of this error and explore the various strategies to free up space and ensure the smooth functioning of your Oracle database.
Understanding the ORA-19815 Error:
The ORA-19815 error is a warning message that indicates the Flash Recovery Area has reached its maximum utilization. This error is usually accompanied by an inability to allocate space for archive logs, leading to the ORA-19809 and ORA-19804 errors.
Resolving ORA-19815 Error:
When faced with the ORA-19815 error, you have several options to consider for freeing up space and resolving the issue:
- Adjust RMAN Retention Policy:
If you’re using Oracle’s Recovery Manager (RMAN), you can modify the retention policy to control the duration for which backup and archived log files are retained. This can help manage the space consumed by these files in the FRA.
- Backup to Tertiary Device:
Backing up files to a tertiary device such as tape using the RMAN `BACKUP RECOVERY AREA` command can help offload data from the FRA, freeing up valuable space.
- Increase FRA Size:
Consider increasing the `db_recovery_file_dest_size` parameter to provide more space for the FRA. This is a straightforward approach to ensure that the FRA has ample storage capacity.
- Delete Unnecessary Files:
You can use the RMAN `DELETE` command to remove unnecessary backup and archived log files. Additionally, if files were deleted using operating system commands, you can employ the RMAN `CROSSCHECK` and `DELETE EXPIRED` commands to synchronize the FRA metadata with the actual files.
Addressing the Root Cause:
In some cases, the ORA-19815 error can be caused by lingering flashback logs that are not released even after resolving space issues in the FRA. This can be attributed to a hardcoded limit on the removal of flashback logs to make space for new archive logs. To address this, follow these steps:
- Identify Flashback Logs:
Determine whether any flashback logs are preventing the FRA from releasing space. You may find that certain restore points created before maintenance could be holding onto these logs.
- Drop Unnecessary Restore Points:
Drop the restore points that are retaining unnecessary flashback logs. This will help to free up space in the FRA.
- Temporarily Disable Flashback Database:
In non-production environments, you can temporarily disable the flashback database feature using the SQL command: ALTER DATABASE FLASHBACK OFF;
- Re-enable Flashback Database:
After resolving the space issue and dropping unnecessary restore points, you can re-enable the flashback database feature using: ALTER DATABASE FLASHBACK ON;
Conclusion:
The ORA-19815 error in Oracle Database 12c is a signal that your Flash Recovery Area is running low on space. By following the steps outlined in this article, you can effectively manage the FRA, address space issues, and ensure the integrity of your backup and recovery processes. Implementing these strategies will help you maintain a smoothly functioning Oracle database environment.
