Message-ID: <48371C8A.7000206@tcdi.com>
Date: Fri, 23 May 2008 15:35:38 -0400
From: Mike Weber <j_weber@tcdi.com>
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To: pgsql-admin@postgresql.org
Subject: 1600 column limit per table
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I ran into the 1600 column upper bound in a table and I am trying to 
assess if I can work around the limit or if I am in need of a re-design 
of my application.  All the documentation on the site that I have seen 
(CREATE TABLE and postgresql.org/about/) says that 1600 is the limit, I 
looked in htup.h and found:

./src/include/access/htup.h:#define MaxHeapAttributeNumber      1600    
/* 8 * 200 */

with documentation to explain the limitation.  The one ray of hope I 
found was a post from 2001(!) suggesting that the maximum number of 
columns can be increased 4x by increasing one's block size to 32k ( 
http://archives.postgresql.org/pgsql-admin/2001-01/msg00199.php )

One thought I had was to join two 1600 column tables but ran into the 
limit of 1664 tuples.

I'm currently using 8.1.10 -- are there any easy outs(via upgrade, 
configuration, or hacking postgres a little) or should I start drawing 
up a different application design?

Thanks,
Mike