Date: Thu, 16 Aug 2018 14:36:02 -0400
From: Stephen Frost <sfrost@snowman.net>
To: Jesper Pedersen <jesper.pedersen@redhat.com>
Cc: Thomas Munro <thomas.munro@enterprisedb.com>,
	Bhushan Uparkar <bhushan.uparkar@gmail.com>,
	pgsql-hackers <pgsql-hackers@postgresql.org>,
	Alexander Korotkov <a.korotkov@postgrespro.ru>
Subject: Re: Index Skip Scan
Message-ID: <20180816183602.GT3326@tamriel.snowman.net>
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Greetings,

* Jesper Pedersen (jesper.pedersen@redhat.com) wrote:
> On 08/16/2018 02:22 AM, Thomas Munro wrote:
> >The idea of starting with DISTINCT was just that it's
> >comparatively easy.  We should certainly try to look ahead and bear
> >those features in mind when figuring out the interfaces though.  Would
> >the indexam skip(scan, direction, prefix_size) operation I proposed be
> >sufficient?  Is there a better way?
>=20
> Yeah, I'm hoping that a Committer can provide some feedback on the direct=
ion
> that this patch needs to take.

Thomas is one these days. :)

At least on first glance, that indexam seems to make sense to me, but
I've not spent a lot of time thinking about it.  Might be interesting to
ask Peter G about it though.

> One thing to consider is the pluggable storage patch, which is a lot more
> important than this patch. I don't want this patch to get in the way of t=
hat
> work, so it may have to wait a bit in order to see any new potential
> requirements.

Not sure where this came from, but I don't think it's particularly good
to be suggesting that one feature is more important than another or that
we need to have one wait for another as this seems to imply.  I'd
certainly really like to see PG finally have skipping scans, for one
thing, and it seems like with some effort that might be able to happen
for v12.  I'm not convinced that we're going to get pluggable storage to
happen in v12 and I don't really agree with recommending that people
hold off on making improvements to things because it's coming.

Thanks!

Stephen

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