Assess students' understanding of concurrency control mechanisms and isolation levels in relational database systems: include locking models (shared/exclusive), optimistic vs. pessimistic concurrency, two‑phase locking (2PL), deadlock detection/prevention, common transaction anomalies (dirty read, non‑repeatable read, phantom), SQL isolation levels (READ UNCOMMITTED, READ COMMITTED, REPEATABLE READ, SERIALIZABLE), and trade-offs between correctness and performance; require analysis of brief transaction interleavings to identify anomalies and recommend appropriate isolation or concurrency strategies.