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Re: overlaps() does not work as expected?

From: Jochem van Dieten <jochemd(at)gmail(dot)com>
To: pgsql-hackers(at)postgresql(dot)org
Subject: Re: overlaps() does not work as expected?
Date: 2005-05-28 13:30:46
Message-ID: f96a9b830505280630c8454e9@mail.gmail.com (view raw or flat)
Thread:
Lists: pgsql-hackers
On 5/28/05, Tom Lane wrote:
> 
> I think they may have intended to treat each time interval
> as the half-open interval [S,T), that is S <= time < T.  However
> that would leave a zero-length interval as completely empty and
> thereby arguably not overlapping anything ... which they didn't
> make it do.

IIRC Jim Melton wrote in one of his books (SQL:1999 or Advanced
SQL:1999, I don't remember) that the intention was to allow easy diary
type comparisons. If you have 2 appointments both with a start and an
end date of 2005-06-09, they overlap. If you have appointments from
08:00 to 10:00 and from 10:00 to 12:00 on that same day, they don't
overlap.

Jochem

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