Re: Two questions.. shared_buffers and long reader issue

Ok thanks.

iostat confirmed it's an IO bottleneck.
Will add some discs to the RAID unit.

Used 4 Raptor discs in Raid 10 until now.


best regards,
    patric


Tom Lane wrote:
> Patric de Waha <lists@p-dw.com> writes:
>
>>    Postgres is running on a dedicated server  P4 DualCore, 4 Gig Ram.
>>
>
> When you don't even mention your disk hardware, that's a bad sign.
> In a database server the disk is usually more important than the CPU.
>
>
>>    Why do long readers influence the rest of the transactions in such a
>> heavy way?
>>    Any configuration changes which can help here?
>>    Is it a disc-IO bottleneck thing?
>>
>
> Very possibly.  Have you spent any time watching "vmstat 1" output
> to get a sense of whether your I/O is saturated?
>
>
>> WAL files are located on another disc than the dbase itself.
>>
>
> That's good, but it only relates to update performance not SELECT
> performance.
>
>
>> effective_cache_size = 5000
>>
>
> That's way too small for a 4G machine.  You could probably stand to
> boost maintenance_work_mem too.  However, neither of these have any
> immediate relationship to your problem.
>
>             regards, tom lane
>