Message-ID: <482D3A60.30006@archonet.com>
Date: Fri, 16 May 2008 08:40:16 +0100
From: Richard Huxton <dev@archonet.com>
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To: kevin kempter <kevin@kevinkempterllc.com>
CC: pgsql-performance@postgresql.org
Subject: Re: Join runs for > 10 hours and then fills up >1.3TB of
 disk space
References: <CEFBA6FF-0E0A-41A0-959E-7DBBDA296825@kevinkempterllc.com>
In-Reply-To: <CEFBA6FF-0E0A-41A0-959E-7DBBDA296825@kevinkempterllc.com>
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kevin kempter wrote:
> Hi List;
> 
> I have a table with 9,961,914 rows in it (see the describe of 
> bigtab_stats_fact_tmp14 below)
> 
> I also have a table with 7,785 rows in it (see the describe of 
> xsegment_dim below)
> 
> I'm running the join shown below and it takes > 10 hours and eventually 
> runs out of disk space on a 1.4TB file system

> QUERY PLAN
> --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 
> 
> Merge Join  (cost=1757001.74..73569676.49 rows=3191677219 width=118)

Dumb question Kevin, but are you really expecting 3.2 billion rows in 
the result-set? Because that's approaching 400GB of result-set without 
any overheads.

-- 
   Richard Huxton
   Archonet Ltd