Re: 2 machines, same database, same query, 10 times slower?

From: Antonio Goméz Soto <antonio(dot)gomez(dot)soto(at)gmail(dot)com>
To: Tomas Vondra <tv(at)fuzzy(dot)cz>
Cc: pgsql-general(at)postgresql(dot)org
Subject: Re: 2 machines, same database, same query, 10 times slower?
Date: 2012-05-09 20:50:39
Message-ID: 4FAAD89F.1030604@gmail.com
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Tomas,

running vacuum full cdr brought down the query time to 4 seconds..

Thanks a lot,
Antonio

Op 08-05-12 21:15, Tomas Vondra schreef:
> On 8.5.2012 20:32, Antonio Goméz Soto wrote:
>>>> Do this on both machines to verify that
>>>>
>>>> SELECT relpages, reltuples FROM pg_class WHERE relname = 'cdr';
>> Slow machine:
>>
>> relpages | reltuples
>> ----------+-----------
>> 400566 | 982321
>>
>> Fast machine:
>>
>> relpages | reltuples
>> ----------+-------------
>> 62076 | 1.48375e+06
>>
>>
>
> Yup, that's probably the culprit. The slow machine has to read 400000
> pages while the fast one just 62000. Each page is 8kB, so this is 3GB
> vs. 500MB difference.
>
> T.
>

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