Date: Mon, 27 Feb 2017 15:29:16 -0500
From: Bruce Momjian <bruce@momjian.us>
To: Michael Paquier <michael.paquier@gmail.com>
Cc: Andreas Karlsson <andreas@proxel.se>,
	Andres Freund <andres@2ndquadrant.com>,
	Robert Haas <robertmhaas@gmail.com>,
	Peter Eisentraut <peter_e@gmx.net>, Jim Nasby <jim@nasby.net>,
	PostgreSQL mailing lists <pgsql-hackers@postgresql.org>
Subject: Re: REINDEX CONCURRENTLY 2.0
Message-ID: <20170227202916.GC421@momjian.us>
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On Fri, Feb 17, 2017 at 11:05:31PM +0900, Michael Paquier wrote:
> On Fri, Feb 17, 2017 at 10:43 PM, Andreas Karlsson <andreas@proxel.se> wrote:
> > Thinking about this makes me wonder about why you decided to use a
> > transaction per index in many of the steps rather than a transaction per
> > step. Most steps should be quick. The only steps I think the makes sense to
> > have a transaction per table are.
> 
> I don't recall all the details to be honest :)
> 
> > 1) When building indexes to avoid long running transactions.
> > 2) When validating the new indexes, also to avoid long running transactions.
> >
> > But when swapping the indexes or when dropping the old indexes I do not see
> > any reason to not just use one transaction per step since we do not even
> > have to wait for any locks (other than WaitForLockers which we just want to
> > call once anyway since all indexes relate to the same table).
> 
> Perhaps, this really needs a careful lookup.
> 
> By the way, as this patch is showing up for the first time in this
> development cycle, would it be allowed in the last commit fest? That's
> not a patch in the easy category, far from that, but it does not
> present a new concept.

FYI, the thread started on 2013-11-15.

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

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +


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