hi, I have strange situation with one table. base info: pg 8.4.8 here is info from pg_stat_all_tables about i: now | relid | n_tup_ins | n_tup_upd | n_tup_del | n_tup_hot_upd | n_live_tup | n_dead_tup | last_autovacuum -------------------------------+-------+-----------+-----------+-----------+---------------+------------+------------+------------------------------ 2011-11-09 21:07:02.250232+00 | xxx | 4184 | 1069977 | 0 | 621580 | 4184 | 0 | 2011-11-09 21:06:35.23673+00 2011-11-09 21:07:22.312616+00 | xxx | 4184 | 1069977 | 0 | 621580 | 4184 | 0 | 2011-11-09 21:06:35.23673+00 2011-11-09 21:07:42.377629+00 | xxx | 4184 | 1069977 | 0 | 621580 | 4184 | 0 | 2011-11-09 21:06:35.23673+00 2011-11-09 21:08:02.491853+00 | xxx | 4184 | 1069977 | 0 | 621580 | 4184 | 0 | 2011-11-09 21:06:35.23673+00 2011-11-09 21:08:22.575746+00 | xxx | 4184 | 1069977 | 0 | 621580 | 4184 | 0 | 2011-11-09 21:06:35.23673+00 2011-11-09 21:08:42.641988+00 | xxx | 4184 | 1069977 | 0 | 621580 | 4184 | 0 | 2011-11-09 21:06:35.23673+00 2011-11-09 21:09:02.705319+00 | xxx | 4184 | 1069977 | 0 | 621580 | 4184 | 0 | 2011-11-09 21:06:35.23673+00 2011-11-09 21:09:22.769856+00 | xxx | 4184 | 1069977 | 0 | 621580 | 4184 | 0 | 2011-11-09 21:06:35.23673+00 2011-11-09 21:09:42.837779+00 | xxx | 4184 | 1069977 | 0 | 621580 | 4184 | 0 | 2011-11-09 21:06:35.23673+00 2011-11-09 21:10:02.903242+00 | xxx | 4184 | 1069977 | 0 | 621580 | 4184 | 0 | 2011-11-09 21:06:35.23673+00 2011-11-09 21:10:23.315874+00 | xxx | 4184 | 1070484 | 0 | 621949 | 4184 | 507 | 2011-11-09 21:06:35.23673+00 2011-11-09 21:10:43.38273+00 | xxx | 4184 | 1070484 | 0 | 621949 | 4184 | 507 | 2011-11-09 21:10:24.161642+00 2011-11-09 21:11:03.44763+00 | xxx | 4184 | 1070484 | 0 | 621949 | 4184 | 507 | 2011-11-09 21:10:24.161642+00 2011-11-09 21:11:23.51432+00 | xxx | 4184 | 1070484 | 0 | 621949 | 4184 | 0 | 2011-11-09 21:11:20.879516+00 2011-11-09 21:11:43.576631+00 | xxx | 4184 | 1070484 | 0 | 621949 | 4184 | 0 | 2011-11-09 21:11:20.879516+00 2011-11-09 21:12:03.643183+00 | xxx | 4184 | 1070484 | 0 | 621949 | 4184 | 0 | 2011-11-09 21:11:20.879516+00 2011-11-09 21:12:23.699986+00 | xxx | 4184 | 1070484 | 0 | 621949 | 4184 | 0 | 2011-11-09 21:11:20.879516+00 2011-11-09 21:12:43.762559+00 | xxx | 4184 | 1070484 | 0 | 621949 | 4184 | 0 | 2011-11-09 21:11:20.879516+00 2011-11-09 21:13:03.8274+00 | xxx | 4184 | 1070484 | 0 | 621949 | 4184 | 0 | 2011-11-09 21:11:20.879516+00 as you can see within ~ 5 minutes, there were no inserts, just some updates. Which explains (kind of) the autovacuum at 21:10:24.161642+00 but why was there another one at 21:11:20.879516+00? In logs I see: 2011-11-09 21:06:35.236 GMT::@:[6957]:LOG: automatic vacuum of table "public.xxx": index scans: 1 pages: 0 removed, 1094 remain tuples: 704 removed, 2990 remain system usage: CPU 0.00s/0.01u sec elapsed 0.10 sec -- 2011-11-09 21:10:24.161 GMT::@:[8161]:LOG: automatic vacuum of table "public.xxx": index scans: 0 pages: 0 removed, 1094 remain tuples: 0 removed, 3516 remain system usage: CPU 0.00s/0.00u sec elapsed 0.05 sec -- 2011-11-09 21:11:20.879 GMT::@:[8467]:LOG: automatic vacuum of table "public.xxx": index scans: 1 pages: 0 removed, 1094 remain tuples: 507 removed, 2938 remain system usage: CPU 0.00s/0.01u sec elapsed 0.01 sec the question basically is - why do we have so many vacuums? especially the ones that don't do anything? Best regards, depesz -- The best thing about modern society is how easy it is to avoid contact with it. http://depesz.com/ -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general