Message-ID: <4C4A8851.3090608@lbl.gov>
Date: Fri, 23 Jul 2010 23:29:37 -0700
From: Gerald Fontenay <gvfontenay@lbl.gov>
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To: pgsql-performance@postgresql.org
Subject: Re: Strange explain on partitioned tables
References: <4C47F8C8.10005@edd.fr> <4C484874.3060609@2ndquadrant.com>	
	<4C4A11CB.6040800@lbl.gov>
	<1279923370.9866.37.camel@jd-desktop.unknown.charter.com>
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Joshua D. Drake wrote:
> On Fri, 2010-07-23 at 15:03 -0700, Gerald Fontenay wrote:
>   
>>> The PostgreSQL partitioning system is aimed to support perhaps a 
>>> hundred inherited tables.  You can expect to get poor performance on 
>>> queries if you create 1000 of them. 
>>>       
>> Hi,
>>
>> Why is that you would expect poor performance for say 1000 or more? I 
>> have a ~1000 inherited tables and I don't see any significant slowdowns. 
>> I only ever access a single inherited table at a time though in this 
>> situation. I suppose I am using inheritance only for organization in 
>> this case...
>>     
>
> It is variable based on workload and as I recall has to do with the
> planning time. As the number of children increases, so does the planning
> time.
>
>   
 

 I do not execute queries against the parent and children tables.
It became obvious that this can be quite slow.
I am asking specifically if I can expect problems in *that* situation, again, where I directly query a single child table only and where I may have thousands. Just like a any other single table query, no?

Thank you,
Gerald