Re: Optimizing nested ConvertRowtypeExpr execution

From: Kyotaro HORIGUCHI <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp>
To: 9erthalion6(at)gmail(dot)com
Cc: andrew(at)tao11(dot)riddles(dot)org(dot)uk, ashutosh(dot)bapat(at)enterprisedb(dot)com, pavel(dot)stehule(at)gmail(dot)com, andres(at)anarazel(dot)de, pgsql-hackers(at)postgresql(dot)org
Subject: Re: Optimizing nested ConvertRowtypeExpr execution
Date: 2018-11-06 08:18:21
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Sorry for the absense.

At Sun, 4 Nov 2018 16:26:12 +0100, Dmitry Dolgov <9erthalion6(at)gmail(dot)com> wrote in <CA+q6zcWMCNNmMQ-csuDf0Pqr1_ESat5-Vcu5uognfS3EaC4Apg(at)mail(dot)gmail(dot)com>
> > On Sun, 4 Nov 2018 at 15:48, Andrew Gierth <andrew(at)tao11(dot)riddles(dot)org(dot)uk> wrote:
> >
> > >>>>> "Dmitry" == Dmitry Dolgov <9erthalion6(at)gmail(dot)com> writes:
> >
> > Dmitry> This patch went through the last tree commit fests without any
> > Dmitry> noticeable activity, but cfbot says it still applies and
> > Dmitry> doesn't break any tests. The patch itself is rather small, and
> > Dmitry> I could reproduce ~20% of performance improvements while
> > Dmitry> running the same scripts under pgbench (although not in all
> > Dmitry> cases), but probably we need to find someone to take over it.
> > Dmitry> Does anyone wants to do so, maybe Kyotaro?
> >
> > I'll deal with it.
> Thanks!

My last comment was the while() loop does nothing. Ashutosh said
that it is on the model of RelabelType.

I examined the code for T_RelabelType again and it is intending
that the ece_mutator can convert something (specifically only
CollateExpr) to RelableType, then reduce the nested Relabels. So
the order is not wrong in this perspective.

So I don't object to the current patch, but it needs test like


Kyotaro Horiguchi
NTT Open Source Software Center

Attachment Content-Type Size
0002-Test-code-for-Optimize-nested-ConvertRowtypExprs.patch text/x-patch 2.4 KB

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