#23 Critical Fix: JADE 7.0.06/7.0.07 - Roll Forward Recovery
Posted: Fri Aug 02, 2013 3:09 pm
A significant issue has been found which may affect data integrity, relating to restoring an on-line backup in JADE 7.0. This issue has been hot-fixed by the JADE Plant in 7.0.06 and 7.0.07. The issue affects only roll-forward recovery, and does not affect normal crash recovery.
The problem may occur when disk cache is constrained during roll-forward recovery of an on-line backup, for a block address beyond the current physical end-of-file. In this situation, if an existing buffer is reassigned for use with the new file and block address the buffer could be returned with incorrect data.
We believe the update logic integrity checking in place will generally detect the incorrect data when an operation is performed on the block, and the roll-forward recovery will fail. Unfortunately it cannot be said that every possible update would similarly be caught. It is possible for incorrect data to be introduced into the recovered system, and only a physical certify of the database files would detect such errors.
As an assurance for production systems, we suggest installing hotfix 7.0.06.039 or 7.0.7.026 as soon as possible.
Once the hot fix has been installed, we recommend that you perform an additional once-only check:
- Create a stand-alone system by recovering an on-line backup
- Perform a physical certify (using the Database Utility) of the recovered system to determine if any data corruption exists.
The problem may occur when disk cache is constrained during roll-forward recovery of an on-line backup, for a block address beyond the current physical end-of-file. In this situation, if an existing buffer is reassigned for use with the new file and block address the buffer could be returned with incorrect data.
We believe the update logic integrity checking in place will generally detect the incorrect data when an operation is performed on the block, and the roll-forward recovery will fail. Unfortunately it cannot be said that every possible update would similarly be caught. It is possible for incorrect data to be introduced into the recovered system, and only a physical certify of the database files would detect such errors.
As an assurance for production systems, we suggest installing hotfix 7.0.06.039 or 7.0.7.026 as soon as possible.
Once the hot fix has been installed, we recommend that you perform an additional once-only check:
- Create a stand-alone system by recovering an on-line backup
- Perform a physical certify (using the Database Utility) of the recovered system to determine if any data corruption exists.