Date: Fri, 22 Feb 2019 12:01:46 -0600
From: Justin Pryzby <pryzby@telsasoft.com>
To: Amit Langote <amitlangote09@gmail.com>
Cc: Amit Langote <Langote_Amit_f8@lab.ntt.co.jp>,
	Tom Lane <tgl@sss.pgh.pa.us>,
	David Rowley <david.rowley@2ndquadrant.com>,
	"Imai, Yoshikazu" <imai.yoshikazu@jp.fujitsu.com>,
	Alvaro Herrera <alvherre@2ndquadrant.com>,
	Pg Hackers <pgsql-hackers@postgresql.org>
Subject: Re: speeding up planning with partitions
Message-ID: <20190222180146.GH28750@telsasoft.com>
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On Sat, Feb 23, 2019 at 02:54:35AM +0900, Amit Langote wrote:
> > On Fri, Feb 22, 2019 at 09:45:38PM +0900, Amit Langote wrote:
> > > I have updated the inheritance expansion patch.
> > >
> > > Patch 0001 rewrites optimizer/utils/inherit.c, so that it allows
> >
> > Thanks for your continued work on this.
> >
> > I applied v23 patch and imported one of our customers' schema, and ran explain
> > on a table with 210 partitions.  With patch applied there are 10x fewer system
> > calls, as intended.
> 
> OK, great.  I guess you were running SELECT?  Just in case you missed,
> the patch to improve UPDATE/DELETE scalability is no longer part of
> this patch series.

Yes, I understand the scope is reduced.

Actually, when I tested last month, I don't think I realized that UPDATE/DELETE
was included.  Otherwise I would've also tested to see if it resolves the
excessive RAM use with many partitions, with the explanation given that query
is being replanned for every partition.

I set target version to v12.
https://commitfest.postgresql.org/22/1778/

Justin