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To: "John Lister" <john.lister-ps@kickstone.com>
cc: pgsql-sql@postgresql.org
Subject: Re: obtaining difference between minimum value and next in size 
In-reply-to: <3BC753A3784F488F98304300B6E437FD@squarepi.com> 
References: <3BC753A3784F488F98304300B6E437FD@squarepi.com>
Comments: In-reply-to "John Lister" <john.lister-ps@kickstone.com>
	message dated "Wed, 17 Nov 2010 15:11:32 +0000"
Date: Wed, 17 Nov 2010 10:42:36 -0500
Message-ID: <27014.1290008556@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>
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"John Lister" <john.lister-ps@kickstone.com> writes:
> Is it possible to obtain the difference between just the minimum price and the next one up per product,

If you're using >= 8.4, try a window function.  LEAD or LAG ought to
do it.

			regards, tom lane