| From: | "Magnus Hagander" <mha(at)sollentuna(dot)net> |
|---|---|
| To: | "Michael Ben-Nes" <miki(at)canaan(dot)co(dot)il>, "postgresql" <pgsql-general(at)postgresql(dot)org> |
| Subject: | Re: Querry and SMP mechine |
| Date: | 2005-08-07 10:28:44 |
| Message-ID: | 6BCB9D8A16AC4241919521715F4D8BCE094667@algol.sollentuna.se |
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| Lists: | pgsql-general |
> Im using postgres 8.0.1 on Debian Sarge with 2 XEON 2.4 HT.
>
> doing cat /etc/cpuinfo shows that linux sees 4 cpu ( the HT effect ).
>
> I noticed that when im runing a big query only one of the
> CPUs become loaded.
>
> Is it normal behavior ? am i missing something ?
Yes, that is normal. Only one CPU per concurrent query is used.
If your load is mostly single or dual sessions runinng queries, you will
probably get a better performance if you disable hyperthreading. If you
normally have a lot of concurrent sessions, HT will probably help your
total performance.
//Magnus
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