Test undergraduate students' understanding of concurrency control in relational databases, covering locking (shared/exclusive locks, lock granularity, deadlocks), MVCC (versioning, visibility, snapshot reads), and SQL isolation levels (Read Uncommitted, Read Committed, Repeatable Read, Serializable), including identification of anomalies (dirty reads, nonrepeatable reads, phantoms), discussion of trade-offs between correctness and performance, and application to short interleaved-transaction traces and isolation/locking strategy selection.