As I have talked about previously, DB2 Version 9 for z/OS introduced over 50+ great new performance features. Many of these features can really benefit your standard DBA operations, improve application performance and increase overall availability of your systems and data.
One of the important new changes in DB2 Version 9 for z/OS is Utilities options and performance improvements which helps your overall maintenance and health of your systems.
Several performance improvements were made within these standard DB2 utilities leveraging improved access and the new big block I/O features within z/OS.
These improvements result in the potential to save a tremendous amount of CPU on many of your daily, weekly and monthly utility jobs.
Analysis and performancefigures published by IBM shows that the following CPU performance improvement potential.
- 0 to 15% Copy Tablespace
- 5 to 20% in Recover index, Rebuild Index, and Reorg Tablespace/Partition
- 5 to 30% in Load
- 20 to 60% in Check Index
- 35% in Load Partition
- 30 to 50% in Runstats Index
- 40 to 50% in Reorg Index
- Up to 70% in Load Replace Partition with NPIs and dummy input
Elimination of BUILD2 Phase
One of the most important items related to the DB2 Version 9 for z/OS Utilities Improvements was the elimination of the BUILD2 phase processing within the standard utilities when rebuilding indexes from the data entries. The BUILD2 phase was the time when DB2 data was unavailable. Eliminating this phase helps availability for all your applications and shorter utility related downtime.
Eliminating the BUILD2 phase provides a dramatic improvement in availability, but could increase the CPU time and the elapsed time because DB2 manages the concurrent applications when one or more partitions are reorganized. Eliminating the BUILD2 phase allowed online reorgs during non-peak processing and provides the DBAs with more opportunity to maintain and improve their systems, database and application performance.
With each new release of DB2, IBM makes important improvements in performance and CPU reduction, like those noted in this recent blog post.