Bruce Momjian wrote:
> On Tue, Apr 25, 2017 at 04:03:53PM +1200, David Rowley wrote:
> > ..On 25 April 2017 at 13:31, Bruce Momjian <bruce@momjian.us> wrote:
> > > The only unusual thing is that this release has ~180 items while most
> > > recent release have had ~220. The pattern I see that there are more
> > > large features in this release than previous ones.
> >
> > Thanks for drafting this up.
> >
> > I understand that it may have been filtered out, but I'd say that
> > 7e534adcdc70 is worth a mention.
> >
> > Users creating BRIN indexes previously would have had to know
> > beforehand that the table would be sufficiently correlated on the
> > indexed columns for the index to be worthwhile, whereas now there's a
> > lesser need for the user to know this beforehand.
>
> I can't see how this can be added to an existing BRIN entry, so it would
> have to be new. The text would be:
>
> Improve accuracy in determining if a BRIN index scan is beneficial
>
> though this not something I would normally mention becuause most users
> don't understand the optimizer choices and just assume it works.
The problem is that previously it was possible for a BRIN index to be
created, and cause some queries to choose it which were faster using
some other index (a btree). The point is that with this change it
becomes more credible to create BRIN indexes without fear that such
queries are going to slow down.
Your proposed text sounds good to me. Authors would be David Rowley and
Emre Hasegeli.
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Álvaro Herrera https://www.2ndQuadrant.com/
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