Postgres Pro
Downloads
Home   >   mailing lists

Re: Is a better way to have the same result of this query? - Mailing list pgsql-performance

From Vernon Wu
Subject Re: Is a better way to have the same result of this query?
Date
Msg-id WT86WQKJPOYW1XHGCAGEIGLLFBACB.3defc3c4@kimiko
Whole thread Raw
In response to Re: Is a better way to have the same result of this query?  (Jochem van Dieten <jochemd@oli.tudelft.nl>)
Responses Re: Is a better way to have the same result of this query?
List pgsql-performance
Tree view 

12/5/2002 1:06:03 PM, Jochem van Dieten <jochemd@oli.tudelft.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

pgsql-performance by date:

Previous
From: Tomasz Myrta
Date:
Subject: Re: Is a better way to have the same result of this
Next
From: Tom Lane
Date:
Subject: Re: ORDER BY ... LIMIT.. performance