About
This page is about the traditional implementation of the rollback journal (as opposed to a write-ahead log rollback journal)
The traditional rollback journal writes changes to the original database whereas the write-ahead log writes change directly to the rollback journal
Implementation
When a change occurs, the traditional rollback journal implements transactions atomicity by:
- writing a copy of the original unchanged content into a separate rollback journal file
- writing changes directly into the database file.
- committing when the rollback journal is deleted.
In the event of a crash or ROLLBACK, the original content contained in the rollback journal is played back into the database file to revert the file to its original state.