> 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