On Mon, 2005-07-25 at 16:17, Ed L. wrote: > Our inserts and updates on an older 7.3.4 cluster are very slow > (0.3s-0.9s) for any/all tables, new and old. I know an upgrade > may be in order, but I have a number of other 7.3.4 legacy > clusters, and I'd really like to understand the cause and if an > upgrade is going to solve this problem (downtime is sensitive, > of course). > > As a test case, I created the following table on both the slow > cluster and a newly created test cluster on the same box: > > create table foo(id integer, msg text) > > I measured less than 10 inserts/second max on the slow cluster. > On the new cluster on the same system, I measured 5000 > inserts/second. So I figure it's something in the system > relations. Autovac had been disabled for a few days at least. > I did a db-wide vacuum/analyze, still no speedup. > > So two questions: 1) Any ideas on what is the cause? 2) How is > this avoided in 7.4.8 or 8.0.3? Did you do a vacuum full? Have you checked for system table / index bloat? Do you create a lot of system objects and drop them frequently (this can cause the above mentioned system table/index bloating) What does the output of vacuum analyze verbose say? ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings
