Date: Sat, 4 Jun 2011 15:15:59 -0400
From: lists-pgsql@useunix.net
To: pgsql-sql@postgresql.org
Subject: Re: selecting records X minutes apart
Message-ID: <20110604191559.GA16254@slacker.ja10629.home>
References: <20110603195253.GE1324@slacker.ja10629.home>
	<isd5s4$86l$1@reversiblemaps.ath.cx>
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On Sat, Jun 04, 2011 at 11:45:08AM +0000, Jasen Betts wrote:
> On 2011-06-03, lists-pgsql@useunix.net <lists-pgsql@useunix.net> wrote:
> >
> > ID	TS (HH:MM)
> > -------------------
> > 0	20:00
> > 0	20:05
> > 0	20:10
> > 1	20:03
> > 1	20:09
> >
> >
> > Does my question make sense?
> 
> no, why is (1,20:04) excluded, but (0,20:05) included?
> both records are 5 minutes from the newest.

Jasen,

(1,20:04) is excluded because it's timestamp is less than 5 minutes from the
previous record with the same ID (1,20:03), (0,20:05) is included for the
opposite reason.

Let me restate my requirement again with a little more detail.  I want to
select records grouped by ID, ordered by timestamp, in ascending order so I'm
starting with the oldest, that are at least X minutes apart.

I hope that helps.

Thanks again,
Wayne