Chapter 26: Further Reading — Locking, Concurrency, and Isolation Levels

IBM Official Documentation

DB2 for z/OS Administration Guide — Concurrency and Locking. Comprehensive reference for lock modes, lock types, and concurrency control on z/OS. Covers IRLM parameters, lock avoidance, and data sharing lock considerations.
DB2 for z/OS Performance Monitoring and Tuning Guide — Locking Chapter. Detailed guidance on monitoring lock activity using traces and IFCIDs. Includes accounting trace field definitions for lock-related metrics.
IRLM Component Guide. Deep technical reference for the Internal Resource Lock Manager, including all startup parameters (NUMLKTS, NUMLKUS, IRLMRWT, DEADLOK) and their interactions.

DB2 LUW Knowledge Center — Concurrency Control. Reference for isolation levels, lock modes, Currently Committed semantics, and SKIP LOCKED DATA. Includes the lock compatibility matrix and escalation behavior. URL: https://www.ibm.com/docs/en/db2/
DB2 LUW Troubleshooting and Tuning Database Performance — Locking Problems. Practical guidance for diagnosing lock contention, escalation, deadlocks, and timeouts using MON_GET functions and event monitors.

Hernandez, Michael J. and John L. Viescas. "SQL Queries for Mere Mortals." While not DB2-specific, Chapter 15 on transactions and concurrency provides an accessible introduction to isolation levels with excellent examples.
Mullins, Craig S. "DB2 Developer's Guide." Part IV covers concurrency and locking in extensive detail, with separate treatment of z/OS and LUW behaviors. The lock compatibility matrix explanations are particularly clear.
Zikopoulos, Paul, George Baklarz, and Leon Katsnelson. "DB2 for Linux, UNIX, and Windows DBA Guide." Chapter on locking and concurrency includes practical tuning guidance for LOCKLIST, MAXLOCKS, and LOCKTIMEOUT with real-world sizing examples.
Padmanabhan, Suresh et al. "DB2 for z/OS: Utilities and Application Performance." Detailed treatment of utility locking (SHRLEVEL options), batch-OLTP coexistence, and partition-level locking strategies.

SG24-8189: "DB2 11 for z/OS Technical Overview." Chapter on concurrency improvements in DB2 11, including lock avoidance enhancements and skip uncommitted behavior.
SG24-8116: "DB2 9 for z/OS Performance Topics." Includes detailed analysis of lock avoidance effectiveness and guidelines for maximizing lock avoidance rates.
SG24-7869: "Optimizing DB2 Queries with IBM Data Studio." Covers how to use EXPLAIN output to understand locking implications of different access paths.
REDP-4333: "Currently Committed Semantics in DB2 for Linux, UNIX, and Windows." Focused treatment of the Currently Committed feature, including architecture, configuration, limitations, and performance impact measurements.

Berenson, Hal et al. "A Critique of ANSI SQL Isolation Levels." ACM SIGMOD, 1995. The seminal paper that rigorously defines the concurrency anomalies and shows that the ANSI SQL standard's isolation level definitions are ambiguous. Essential reading for understanding why different databases implement isolation levels differently.
Gray, Jim and Andreas Reuter. "Transaction Processing: Concepts and Techniques." Morgan Kaufmann, 1992. The definitive textbook on transaction processing. Part II on concurrency control covers two-phase locking, deadlock detection, and isolation levels with mathematical rigor. Chapter 7 on lock implementation is directly applicable to understanding DB2's IRLM.
Weikum, Gerhard and Gottfried Vossen. "Transactional Information Systems." Morgan Kaufmann, 2001. Advanced textbook covering formal models of concurrency control, including serializability theory, lock-based protocols, and multi-version concurrency control.

IDUG (International DB2 Users Group) Conference Sessions. IDUG regularly features sessions on locking and concurrency tuning. Search the IDUG content library for sessions by DB2 performance specialists on lock escalation prevention and deadlock analysis.
IBM Think Conference — DB2 Performance Track. Annual sessions on DB2 performance include locking optimization techniques and real-world case studies from large DB2 installations.

DB2 for z/OS and LUW Performance Discussion Forums. IBM's DeveloperWorks (now IBM Community) forums contain years of practical Q&A on locking problems. Searching for specific error codes (-911, lock escalation) yields useful real-world troubleshooting advice.
Craig Mullins' DB2 Portal (www.craigsmullins.com). Long-running blog with practical articles on DB2 locking, including "Understanding DB2 Locking" and "Avoiding Deadlocks in DB2."

IBM Data Studio. Includes visual lock analysis tools that display lock chains, deadlock graphs, and lock escalation events in a graphical interface.
IBM OMEGAMON for DB2 (z/OS). Real-time monitoring of lock activity, including lock wait chains, escalation events, and deadlock visualization. The "lock analysis" component provides immediate visibility into production lock problems.
db2top (LUW). Interactive command-line monitoring tool that displays real-time lock statistics, including lock waits, escalations, and deadlocks. Launch with db2top -d MERIDIANDB and press 'l' for the lock screen.

Chapter 9: Transaction Management — Foundation for understanding COMMIT, ROLLBACK, and transaction boundaries.
Chapter 15: Buffer Pool Tuning — Lock memory (LOCKLIST) competes with buffer pool memory for system resources.
Chapter 17: Indexing Strategies — Good indexes reduce the number of rows examined, directly reducing lock acquisition under RS and RR.
Chapter 22: EXPLAIN and Access Paths — Understanding access paths is essential for predicting locking behavior (tablespace scan under RR locks everything).
Chapter 27: Performance Diagnosis Methodology — Lock-bound problems are one of the four bottleneck categories diagnosed using the methodology in the next chapter.