Module 4: Transactions

This PSET covers Module 4: conflict serializability, conflict graphs, Strict Two-Phase Locking (S2PL), MVCC and snapshot isolation, Write-Ahead Logging (WAL), and crash recovery. It starts with concept checks, then builds to two conflict-graph and two WAL-recovery scenarios (one medium and one challenge of each). Before starting, you should have read the Module 4 content, attended the lectures, and completed the matching Colab walkthrough in your CA section.

Tip: The update function for all WAL scenarios is f(x) = x × 1.2.