From: "Christian Paul Cosinas" <cpc@cybees.com>
To: "'PFC'" <lists@peufeu.com>, <pgsql-performance@postgresql.org>
Subject: Re: Speed Up Offset and Limit Clause
Date: Wed, 17 May 2006 09:51:05 -0000
Message-ID: <00e101c67997$6aa049f0$1e21100a@ghwk02002147>
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I am creating an application that gets the value of a large table and write
it to a file.

Why I want to use offset and limit is for me to create a threaded
application so that they will not get the same results.

For example:

Thread 1 : gets offset 0 limit 5000
Thread 2 : gets offset 5000 limit 5000
Thread 3 : gets offset 10000 limit 5000

And so on...

Would there be any other faster way than what It thought?

-----Original Message-----
From: PFC [mailto:lists@peufeu.com] 
Sent: Thursday, May 11, 2006 7:06 AM
To: Christian Paul Cosinas; pgsql-performance@postgresql.org
Subject: Re: [PERFORM] Speed Up Offset and Limit Clause


	Why do you want to use it this way ?
	Explain what you want to do, there probably is another faster
solution...

On Thu, 11 May 2006 16:45:33 +0200, Christian Paul Cosinas  
<cpc@cybees.com> wrote:

> Hi!
>
> How can I speed up my server's performance when I use offset and limit
> clause.
>
> For example I have a query:
> SELECT * FROM table ORDER BY id, name OFFSET 100000 LIMIT 10000
>
> This query takes a long time about more than 2 minutes.
>
> If my query is:
> SELECT * FROM table ORDER BY id, name OFFSET 50000 LIMIT 10000
> It takes about 2 seconds.
>
> Thanks
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 9: In versions below 8.0, the planner will ignore your desire to
>        choose an index scan if your joining column's datatypes do not
>        match