DB2 10 Conversion Mode
Reduce resource consumption on DB2 10 for z/OS
The performance of high concurrent inserts is better in DB2 10, with tests showing a typical range of 5- to 40- percent reduction in CPU time when compared with DB2 9 performance. Higher CPU performance is achieved when processing sequential inserts. The amount of improvement also depends on the table-space type, with Universal Table Spaces seeing higher improvements.
When a series of inserts are sequential with respect to the cluster key–but the key is less than the highest key in the index–a new page-selection algorithm helps minimize getpages, which can help reduce CPU cost.
DB2 10 contains some referential integrity-checking improvements on inserts that may result in reduced CPU utilization and I/O processing.
Utilities and Large Objects
Generally speaking, DB2 utility CPU performance in DB2 10 is equivalent to that of DB2 9, but DB2 9 already introduced performance improvements of up to 50 percent CPU savings compared to DB2 8 for various utilities processing.
DB2 10 also contains numerous large object (LOB) enhancements and one of them applies to Conversion Mode, namely LOB materialization avoidance. For LOBs, IBM has observed up to a 16-percent reduction in CPU consumption for DDF Inserts.
Add Up the Savings
All of the CPU savings described here apply to Conversion Mode. Some of the performance improvements are available upon installation of DB2 10, without additional changes, while others require very minimal changes, such as a change to installation parameters. Some require a System z10 processor and perhaps changing the buffer-pool parameters. Most require appropriate rebinds to fully realize the benefits. Additional CPU benefits can be obtained when migrating to New Function Mode, which will be outlined in a future article.