Re: update statistics slowing system

Posted in 2003

Art S. Kagel — Thu, 13 Nov 2003 17:30:40 -0500 — source: Usenet: comp.databases.informix

On Wed, 12 Nov 2003 15:10:19 -0500, Glen Johnson wrote: > Should doing an update statistics on a table in one database affect the > preformance of users in a totally separate database. Does it lock some global > tables? I don't think it is a CPU problem since this is on a 6 processor > Linux system. It depends. If you are running the UPDATE STATISTICS with a high PDQPRIORITY level it can lock up CPU and memory resources from other sessions with PDQPRIORITY > 1. Also note Jonathan's point about versions and comments about buffers if your BUFFERS is set too low. Finally, if you are not using the PSORT_ environment variables in the UPDATE STATS session's environment then the extensive sorting will tie up engine resources (PSORT_ requires PDQPRIORITY>1 just don't get carried away). Art S. Kagel