On Friday May 7 2004 9:09, Tom Lane wrote: > "Ed L." <pgsql@bluepolka.net> writes: > > I guess the activity just totally outran the ability of autovac to keep > > up. > > Could you have been bit by autovac's bug with misreading '3e6' as '3'? > If you don't have a recent version it's likely to fail to vacuum large > tables often enough. No, our autovac logs the number of changes (upd+del for vac, upd+ins+del for analyze) on each round of checks, and we can see it was routinely performing when expected. The number of updates/deletes just far exceeded the thresholds. Vac threshold was 2000, and at times there might be 300,000 outstanding changes in the 10-30 minutes between vacuums. Given the gradual performance degradation we saw over a period of days if not weeks, and the extremely high numbers of unused tuples, I'm wondering if there is something like a data fragmentation problem occurring in which we're having to read many many disk pages to get just a few tuples off each page? This cluster has 3 databases (2 nearly idle) with a total of 600 tables (about 300 in the active database). Gzipped dumps are 1.7GB. max_fsm_relations = 1000 and max_fsm_pages = 10000. The pattern of ops is a continuous stream of inserts, sequential scan selects, and deletes. ---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend
