Message-ID: <4BEC0564.7020403@magwerks.com>
Date: Thu, 13 May 2010 09:57:56 -0400
From: Justin Graf <justin@magwerks.com>
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To: pgsql-sql@postgresql.org, vindex+lists-pgsql-sql@apartia.org
Subject: Re: best paging strategies for large datasets?
References: <20100512054144.GA8762@apartia.fr> <4BEAD6A9.5040906@magwerks.com>
	<20100513074353.GA19779@apartia.fr>
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On 5/13/2010 3:43 AM, Louis-David Mitterrand wrote:
**snip***
>
>> What do you mean by quite slow??
>>      
> Like several seconds. I have to cache the results.
>    

Well then i suggest posting the queries to Performance or here and let 
us take a look them
don't forget to include the explain/analyze, and number of records in 
each table.
>> On a 30K record table count() and query speed should not be a problem..
>>      
> This query is a large multi-join of times series data, not a single
> table. And it's not (prematurely :) optimized.
>
> I'm planning a materialized view for it.
>    

here read this
http://www.pgcon.org/2008/schedule/events/69.en.html

The question that begs to be asked how big are the tables the query is 
accessing??

if its not hundreds of thousands to millions of records or on a stone 
age Server , my guess is  the  query can be improved.


> **snip**
>> RecordCount/Limit = Number of pages
>> CurrentPage = (offset%RecordCount)/Limit
>>      
> These simple formulas we bill handy.
>    

don't forget to use floor on these in what ever language your 
programming in


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