Re: using an index worst performances - Mailing list pgsql-performance

From Gaetano Mendola
Subject Re: using an index worst performances
Date
Msg-id 412505F6.6080000@bigfoot.com
Whole thread Raw
In response to Re: using an index worst performances  (Richard Huxton <dev@archonet.com>)
Responses Re: using an index worst performances
List pgsql-performance
Richard Huxton wrote:

> Gaetano Mendola wrote:
>
>> Hi all,
>> I'm tring to optimize the following query:
>>
>> http://rafb.net/paste/results/YdO9vM69.html
>>
>> as you can see from the explain after defining the
>> index the performance is worst.
>>
>> If I raise the default_statistic_target to 200
>> then the performance are worst then before:
>>
>>
>> Without index: 1.140 ms
>> With index: 1.400 ms
>> With default_statistic_targer = 200:   1.800 ms
>
>
> Can I just check that 1.800ms means 1.8 secs (You're using . as the
> thousands separator)?
>
> If it means 1.8ms then frankly the times are too short to mean anything
> without running them 100 times and averaging.


It mean 1.8 ms and that execution time is sticky to that value even
with 1000 times.


Regards
Gaetano Mendola

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