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Re: Strange explain on partitioned tables

From: "Joshua D(dot) Drake" <jd(at)commandprompt(dot)com>
To: gvfontenay(at)lbl(dot)gov
Cc: pgsql-performance(at)postgresql(dot)org
Subject: Re: Strange explain on partitioned tables
Date: 2010-07-23 22:16:10
Message-ID: 1279923370.9866.37.camel@jd-desktop.unknown.charter.com (view raw or flat)
Thread:
Lists: pgsql-performance
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.

Joshua D. Drake


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