Locking is the generic term used to refer to the database management system function that is required for managing interprocess concurrency and maintaining data integrity. However, locking is just one of the serialization mechanisms available in IBM® DB2® for z/OS®. DB2 uses different mechanisms for serialization to achieve its goal of maximizing concurrency without losing integrity with a minimum cost in CPU, I/O, and storage resources.

In this IBM Redbooks® publication, we review and explore the different serialization mechanisms used in DB2, such as transaction (DML) locking, claims and drains, restrictive states, latching, and optimistic serialization.

This book was written for application developers in order to help them better understand serialization mechanisms and how they influence application design decisions.

Part 1. Concurrency and integrity

Chapter 1. Serialization

Chapter 2. Transaction locking

Chapter 3. Serialization techniques

Part 2. Application concurrency and lock optimization

Chapter 4. Database design considerations

Chapter 5. Application design

Chapter 6. Utilities, commands, and SQL

Chapter 7. System considerations

Part 3. Monitoring and problem determination

Chapter 8. Identifying locking and concurrency problems

Chapter 9. Analyzing concurrency problems

Part 4. Data sharing

Chapter 10. Global locking

Chapter 11. Monitoring data sharing locking activity

Chapter 12. Database and application design in data sharing

Appendix A. System topology and workload