Week 11#
Lecturer: Uma Maheswari, Faculty for BITS Pilani WILP
Date: 30Oct/2021
2PL#
Basic#
All locks are obtained in growth phase and during shrinking phase all the unlocks are done
Conservative#
All locks are obtained before any transactions and all are unlocked after transactions
Strict#
Exclusive locks are unlocked after a commit, shared locks
Rigourous#
All locks are unlocked after a commit
Problems on Locking#
Basic 2PL
Strict 2PL
No growth or shrinking phase so not in 2PL
Deadlock#
Problems#
No deadlocks
Deadlock happens because the two processes are waiting for each other