HPE Shadowbase UNDO
The Shadowbase UNDO product utilizes a standard data replication engine in a modified configuration to remove the corruption while the application optionally continues its operation.
Key Features
Uses the Database Management System (DBMS) change-data to reverse the database to a state that is known to be correct
Can be performed while the application remains online and available for processing both update and read-only requests
Reads the DBMS change-queue to access the events involved in the corruption when database corruption is known or suspected
Reads from either the start point of corruption to the end point, or conversely, from the end point to the start point, frequently supplied as date/time values or as change-queue location values
Database changes often saved by the DBMS into an intermediate undo queue to identify the events needing undone
Can be repeated until the user is satisfied that the undo queue properly captures the corruption events
Events in the undo queue are read, processed, and applied in reverse order to the original occurrence in order to back out or undo the original changes:
- A commit work is replaced by a begin work
- A begin work is replaced by a commit work
- An insert is replaced with a delete
- A delete is replaced by an insert
- The before and after images of an update are switched (the after image of the update is applied)