Re: [HACKERS] PG 10 release notes

On Mon, Apr 24, 2017 at 08:52:05PM -0700, Andres Freund wrote:
> On 2017-04-24 23:45:06 -0400, Tom Lane wrote:
> > Andres Freund <andres@anarazel.de> writes:
> > > On 2017-04-24 23:37:42 -0400, Bruce Momjian wrote:
> > >> I remember seeing those and those are normally details I do not put in
> > >> the release notes as there isn't a clear user experience change except
> > >> "Postgres is faster".  Yeah, a bummer, and I can change my filter, but
> > >> it would require discussion.
> > 
> > > I think "postgres is faster" is one of the bigger user demands, so I
> > > don't think that policy makes much sense.  A large number of the changes
> > > over the next few releases will focus solely on that.  Nor do I think
> > > past release notes particularly filtered such changes out.
> > 
> > I think it has been pretty common to accumulate a lot of such changes
> > into generic entries like, say, "speedups for hash joins".  More detail
> > than that simply isn't useful to end users; and as a rule, our release
> > notes are too long anyway.
> 
> Oh, I completely agree with accumulating related changes, and that
> code-level details aren't useful.  I think we skipped them entirely
> here.  And I just listed my own changes because I could find them
> quickly, but they're not alone, e.g:
> 090010f2ec9b1f9ac1124dc628b89586f911b641 - Improve performance of find_tabstat_entry()/get_tabstat_entry()
> which makes it realistic to have sessions touching many relations, which
> previously was O(#relations^2), and which caused repeated complaints
> over the years, and allows for different usecases.

Looking at this commit it appears to improve pg_stat statistics handling.
I don't see how that improves performance except to improve statistics
aggregation, which happens in the statistics process.

--  Bruce Momjian  <bruce@momjian.us>        http://momjian.us EnterpriseDB
http://enterprisedb.com

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