If transaction aborts, private workspace is deleted and private blocks put on free list. If transaction commits, private workspace index replaces previous index and old blocks put on free list. Update file but save original values in case rollback is needed. Log written to before file updated. Server sets lock labelled with TID on each data item before access.
Server unlocks data items after commit.
Most common method. New locks are acquired. Reduces inconsistency and deadlocks. All reads by later transactions are good. No reads of aborted transactions.