Commit List Management
Maintain and periodically recompute a tid T-Oldest, such that
- Every active txn’s tid is greater than T-Oldest
- Every new tid is greater than T-Oldest
- For every committed transaction with tid ? T-Oldest, its versions are committed
- For every aborted transaction with tid ? T-Oldest, its versions are wiped out
Queries don’t need to know tids ? T-Oldest
- So only maintain the commit list for tids > T-Oldest