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Re: test / live environment, major performance difference

From: Christo Du Preez <christo(at)mecola(dot)com>
To: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: test / live environment, major performance difference
Date: 2007-06-12 16:59:16
Message-ID: 466ED0E4.3040803@mecola.com (view raw or flat)
Thread:
Lists: pgsql-performance
Yes, I have just about tried every combination of vacuum on the
database. Just to make 100% sure.

Tom Lane wrote:
> Christo Du Preez <christo(at)mecola(dot)com> writes:
>   
>> On my laptop the explain analyze looks like this:
>>     
>
>   
>> "Index Scan using fki_layertype_parentid on layertype  (cost=0.00..8.27
>> rows=1 width=109)"
>> "  Index Cond: (parentid = 300)"
>>     
>
> OK ...
>
>   
>> and on the problem server:
>>     
>
>   
>> "Seq Scan on layertype  (cost=0.00..20.39 rows=655 width=110)"
>> "  Filter: (parentid = 300)"
>>     
>
> The server thinks that every row of the table matches the WHERE clause.
> That being the case, it's making the right choice to use a seqscan.
> The question is why is the rows estimate so far off?  Have you ANALYZEd
> the table lately?
>
> 			regards, tom lane
>
>
>   

-- 
Christo Du Preez

Senior Software Engineer
Mecola IT
Mobile:	 +27 [0]83 326 8087
Skype:	 christodupreez
Website: http://www.locateandtrade.co.za


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Subject: Re: test / live environment, major performance difference
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Subject: Re: VACUUM vs auto-vacuum daemon

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