Q and A

Asked and Answered

Would you recommend turning on intra-parallelism on a DB2 Enterprise-Extended Edition (EEE) data warehouse database?

Scott Hayes responds:

Generally, I recommend Intra_Parallel = YES for a data warehouse environment, whether its DB2 Enterprise Edition or EEE, but there are exceptions. I would need to know how many physical partitions and how many nodes or logical partitions you have. The CPU busy rate across the physical partitions is a factor to consider, along with how many users would typically have concurrently running queries.

You told me you have one physical partition (an IBM P690 server running AIX 5.1 with eight CPUs and 32GB of memory) and eight logical partitions and a mixed transaction environment (OLTP during the day, decision support in the evening) with 135 connections scalable to 300 and approximately 25 to 50 percent concurrent queries. Your current CPU is 50 to 90 percent utilized on each of the CPUs, depending on load.

With the current configuration you have described, I would say you are making good use of inter-partition parallelism. Turning on intra-partition parallelism would probably have adverse performance consequences. I wouldn't consider intra-partition parallelism until there is a 4:1 ratio of CPUs to partitions, and then I'd only engage intra-partition parallelism if the CPU busy rate runs less than 50 percent on average.

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