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).
This article starts a serial devoted to Db2 for z/OS System Profiles. Profiles are still not widely used and known while they represent a strong capability allowing to automatically tune the system. This introductory article discusses how you can define and activate a system profile.
Starting in Db2 Version 126.96.36.199, 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:
While system failures seldom happen, most customers expect crash recovery to complete quickly. Our development team decided upon a solution which promised increased availability, without risking the distinguished resilience that Db2 has achieved over the decades.
Investigating performance problems doesn’t have to be hard. There are some basic steps you can take to find common bottlenecks in your system – ‘performance first aid’ if you will. We’re going to look at some of these basic problems and how to find them, using monreport.dbsummary & friends.