Re: Performance Bottleneck - Mailing list pgsql-performance

From Martin Foster
Subject Re: Performance Bottleneck
Date
Msg-id 41140D17.7070101@ethereal-realms.org
Whole thread Raw
In response to Re: Performance Bottleneck  (Gaetano Mendola <mendola@bigfoot.com>)
Responses Re: Performance Bottleneck  (Gaetano Mendola <mendola@bigfoot.com>)
Re: Performance Bottleneck  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-performance
Gaetano Mendola wrote:
>
>
> Let start from your postgres configuration:
>
> shared_buffers = 8192    <==== This is really too small for your
> configuration
> sort_mem = 2048
>
> wal_buffers = 128    <==== This is really too small for your configuration
>
> effective_cache_size = 16000
>
> change this values in:
>
> shared_buffers = 50000
> sort_mem = 16084
>
> wal_buffers = 1500
>
> effective_cache_size = 32000
>
>
> to bump up the shm usage you have to configure your OS in order to be
> allowed to use that ammount of SHM.
>
> This are the numbers that I feel good for your HW, the second step now is
> analyze your queries
>

These changes have yielded some visible improvements, with load averages
rarely going over the anything noticeable.   However, I do have a
question on the matter, why do these values seem to be far higher then
what a frequently pointed to document would indicate as necessary?

http://www.varlena.com/GeneralBits/Tidbits/perf.html

I am simply curious, as this clearly shows that my understanding of
PostgreSQL is clearly lacking when it comes to tweaking for the hardware.

    Martin Foster
    Creator/Designer Ethereal Realms
    martin@ethereal-realms.org



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