Re: Serious issues with CPU usage
От | Manfred Koizar |
---|---|
Тема | Re: Serious issues with CPU usage |
Дата | |
Msg-id | g8qolvoau4dabgqprbn1abde81f61eol5l@email.aon.at обсуждение исходный текст |
Ответ на | Re: Serious issues with CPU usage (Andri Saar <andris@estpak.ee>) |
Список | pgsql-performance |
On Mon, 8 Sep 2003 13:50:23 +0300, Andri Saar <andris@estpak.ee> wrote: >Basically I do this: >1) select about ~700 ID's I have to poll >2) poll them >3) update those 700 rows in that "table" I used (~2700 rows total). > >And I do this cycle once per minute, so yes, I've got a zillion updates. 700 >of 2700 is roughly 25%, so I'd have to vacuum once per minute? With such a small table VACUUM should be a matter of less than one second: fred=# vacuum verbose t; INFO: --Relation public.t-- INFO: Index t_pkey: Pages 65; Tuples 16384: Deleted 4096. CPU 0.01s/0.10u sec elapsed 0.21 sec. INFO: Removed 4096 tuples in 154 pages. CPU 0.04s/0.02u sec elapsed 0.07 sec. INFO: Pages 192: Changed 192, Empty 0; Tup 16384: Vac 4096, Keep 0, UnUsed 0. Total CPU 0.08s/0.16u sec elapsed 0.36 sec. VACUUM Time: 415.00 ms And this is on a 400 MHz machine under cygwin, so don't worry if you have a real computer. Servus Manfred
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