Re: difference in query performance due to the inclusion of a polygon geometry field

From: John R Pierce <pierce(at)hogranch(dot)com>
To: pgsql-general(at)postgresql(dot)org
Subject: Re: difference in query performance due to the inclusion of a polygon geometry field
Date: 2012-11-30 21:46:50
Message-ID: 50B9294A.3070807@hogranch.com
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On 11/30/12 8:30 AM, Ivan Marchesini wrote:
> Thanks but as I said I have tried using psql directly on the server.
> And still there is a strong difference between the queries execution
> time with and without the geometric field.
> May be it is a problem of clients but I obtain the same problem with
> pgadmin, psql and other servers. So I suppose it is not. :-)

query without Geometry is returning 1474 tuples of 133 bytes each.
thats about 200 kbytes worth of tuples which have to be sorted, then
converted to client format.

query WITH geometry is returning 1474 tuples of 196111 bytes each. thats
about 300MB which have to be sorted, then converted to client format.

you're surprised handling 300MB takes longer than 200KB?

--
john r pierce N 37, W 122
santa cruz ca mid-left coast

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