Summary, cont.
Serializability allows us to “simulate” serial execution with better performance.
2PL: A simple mechanism to get serializability.
- Strict 2PL also gives us recoverability, ACA
Lock manager module automates 2PL so that only the access methods worry about it.
- Lock table is a big main-mem hash table
Deadlocks are possible, and typically a deadlock detector is used to solve the problem.