Date: Fri, 13 Sep 2019 13:03:06 -0300
From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Michael Paquier <michael@paquier.xyz>,
	Masahiko Sawada <sawada.mshk@gmail.com>,
	Tatsuro Yamada <tatsuro.yamada.tf@nttcom.co.jp>,
	Rafia Sabih <rafia.pghackers@gmail.com>,
	Dmitry Dolgov <9erthalion6@gmail.com>, Peter Geoghegan <pg@bowt.ie>,
	PostgreSQL-development <pgsql-hackers@postgresql.org>,
	Jeff Janes <jeff.janes@gmail.com>,
	Thomas Munro <thomas.munro@enterprisedb.com>,
	Michael Paquier <michael.paquier@gmail.com>,
	Peter Eisentraut <peter.eisentraut@2ndquadrant.com>
Subject: Re: [HACKERS] CLUSTER command progress monitor
Message-ID: <20190913160306.GA1533@alvherre.pgsql>
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On 2019-Sep-13, Robert Haas wrote:

> On Fri, Sep 13, 2019 at 2:49 AM Michael Paquier <michael@paquier.xyz> wrote:
> > On Fri, Sep 06, 2019 at 08:10:58AM -0400, Robert Haas wrote:
> > > It's fine if things are updated as well -- it's just you need to make
> > > sure that those places know whether or not they are supposed to be
> > > doing those updates. Again, why can't we just pass down a value
> > > telling them "do reindex-style progress updates" or "do cluster-style
> > > progress updates" or "do no progress updates"?
> >
> > That's invasive.  CREATE INDEX reporting goes pretty deep into the
> > tree, with steps dedicated to the builds and scans of btree (nbtsort.c
> > for example) and hash index AMs.

> Well, if CREATE INDEX progress reporting can't be reasonably done
> within the current infrastructure, then it should be reverted for v12
> and not committed again until somebody upgrades the infrastructure.

Ummm ... I've been operating --in this thread-- under the assumption
that it is REINDEX to blame for this problem, not CREATE INDEX, because
my recollection is that I tested CREATE INDEX together with CLUSTER and
it worked fine.  Has anybody done any actual research that the problem
is to blame on CREATE INDEX and not REINDEX?

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services