Thanks to everyone for the feedback about vacuuming. It's been very useful. The pointers to the pgstattuple and Pgfouine tools were also helpful. I'm now considering the following plan for trying Autovacuuming again with 8.1. I'd like any peer review you have to offer of the following: 1. First, I'll move the settings to match the defaults in 8.2. The ones I noticed in particular were: autovacuum_vacuum_threshold changes: 1000 -> 500 autovacuum_anayze_threshold changes: 500 -> 250 autovacuum_scale_factor changes: .4 -> .2 autovacuum_analyze_scale_factor changes .2 -> .1 2. Try the vacuum cost delay feature, starting with a 20ms value: autovacuum_vacuum_cost_delay = 20 3. Immediately add a row to pg_autovacuum for a huge logging table that would be too slow to vacuum usually. We'll still vacuum it once a week for good measure by cron. 4. For good measure, I think I still keep the nightly cron entry that does a complete vacuum analyze (except for that large table...). Seem like a reasonable plan? Mark
