Date: Sun, 8 Mar 2020 03:45:05 +0100
From: David Fetter <david@fetter.org>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Paul A Jungwirth <pj@illuminatedcomputing.com>,
	Alvaro Herrera <alvherre@2ndquadrant.com>,
	Pavel Stehule <pavel.stehule@gmail.com>,
	Jeff Davis <pgsql@j-davis.com>,
	Pgsql Hackers <pgsql-hackers@postgresql.org>
Subject: Re: range_agg
Message-ID: <20200308024505.GW13804@fetter.org>
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 <20200307221312.GV13804@fetter.org>
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On Sat, Mar 07, 2020 at 06:45:44PM -0500, Tom Lane wrote:
> David Fetter <david@fetter.org> writes:
> > There's another use case not yet covered here that could make this
> > even more complex, we should probably plan for it: multi-ranges
> > with weights.
> 
> I'm inclined to reject that as completely out of scope.  The core
> argument for unifying multiranges with ranges, if you ask me, is to
> make the data type closed under union.  Weights are from some other
> universe.

I don't think they are. SQL databases are super useful because they do
bags in addition to sets, so set union isn't the only, or maybe even
the most important, operation over which ranges ought to be closed.

Best,
David.
-- 
David Fetter <david(at)fetter(dot)org> http://fetter.org/
Phone: +1 415 235 3778

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