On Wed, 2006-11-01 at 14:15 -0500, Steven Flatt wrote: > Here is a potential problem with the auto-vacuum daemon, and I'm > wondering if anyone has considered this. To avoid transaction ID > wraparound, the auto-vacuum daemon will periodically determine that it > needs to do a DB-wide vacuum, which takes a long time. On our system, > it is on the order of a couple of weeks. (The system is very busy and > there is a lot of I/O going on pretty much 24/7). During this period > of time, there is nothing to automatically analyze any of the tables, > leading to further performance problems. What are your thoughts on > having the DB-wide vacuum running on a separate thread so that the > daemon can concurrently wake up and take care of analyzing tables? Yes, do it. Every couple of weeks implies a transaction rate of ~~500tps, so I'd be interested to hear more about your system. -- Simon Riggs EnterpriseDB http://www.enterprisedb.com
