Re: Is a better way to have the same result of this query?

From: Vernon Wu <vernonw(at)gatewaytech(dot)com>
To: Jochem van Dieten <jochemd(at)oli(dot)tudelft(dot)nl>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Is a better way to have the same result of this query?
Date: 2002-12-05 21:23:16
Message-ID: WT86WQKJPOYW1XHGCAGEIGLLFBACB.3defc3c4@kimiko
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-performance

12/5/2002 1:06:03 PM, Jochem van Dieten <jochemd(at)oli(dot)tudelft(dot)nl> wrote:

>You start by using a dataset of realistic size. Sorry, but if the actual
>time is < 10.00 ms it is rather pointless to optimize further since
>chance is going to be the biggest factor. And the IN/EXISTS difference
>is dependent on dataset size.
>

Do you mean that using "EXIST" is not necessary out-perform using 'IN" even the "explain" say so? What is the right
size for those two key words?

Thanks for your very hepful information.

Vernon

In response to

Responses

Browse pgsql-performance by date

  From Date Subject
Next Message Tom Lane 2002-12-05 22:00:09 Re: ORDER BY ... LIMIT.. performance
Previous Message Tomasz Myrta 2002-12-05 21:19:58 Re: Is a better way to have the same result of this