Db2 11.5 is here and with it comes a bunch of new features and changed behaviors in the area of Availability & Recovery that should make your every day tasks easier. Check out the list that includes items like Advanced Log Space Management, Reduced Logging and better HADR Reads on Standby.
A database lock is a mechanism utilized by Db2 to govern the access to a database object amongst different transactions. This article describes the locking mechanism for Db2 (for LUW).
Locking and latching are both key mechanisms employed by relational database management systems to ensure data integrity, consistency, and the serialization of resources. In the Db2 for z/OS IRLM manages the locks, but both Db2 and IRLM have internal latches.
Steve Thomas of CA Technologies presents a great introduction into the world of locks, latches, claims and drains. A must see for all developers working wit Db2 for z/OS as well as all DBAs wanting to refresh their knowledge.
Starting in Db2 Version 220.127.116.11, a new feature called 'DB2_AVOID_LOCK_ESCALATION' provides control over lock escalation behaviour. The feature is configured through a dynamic (no instance recycling needed) registry variable: