Horton

Re: ALTER tbl rewrite loses CLUSTER ON index

Justin Pryzby <pryzby@telsasoft.com>

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From: Justin Pryzby <pryzby@telsasoft.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, Amit Langote <amitlangote09@gmail.com>, pgsql-hackers@postgresql.org, Michael Paquier <michael@paquier.xyz>
Date: 2020-02-29T16:52:58Z
Lists: pgsql-hackers

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On Fri, Feb 28, 2020 at 08:42:02PM -0600, Justin Pryzby wrote:
> On Fri, Feb 28, 2020 at 06:26:04PM -0500, Tom Lane wrote:
> > Justin Pryzby <pryzby@telsasoft.com> writes:
> > > I think the attached is 80% complete (I didn't touch pg_dump).
> > > One objection to this change would be that all relations (including indices)
> > > end up with relclustered fields, and pg_index already has a number of bools, so
> > > it's not like this one bool is wasting a byte.
> > > I think relisclustered was a's clever way of avoiding that overhead (c0ad5953).
> > > So I would be -0.5 on moving it to pg_class..
> > > But I think 0001 and 0002 are worthy.  Maybe the test in 0002 should live
> > > somewhere else.
> > 
> > 0001 has been superseded by events (faade5d4c), so the cfbot is choking
> > on that one's failure to apply, and not testing any further.  Please
> > repost without 0001 so that we can get this testing again.
> 
> I've just noticed while working on (1) that this separately affects REINDEX
> CONCURRENTLY, which would be a new bug in v12.  Without CONCURRENTLY there's no
> issue.  I guess we need a separate patch for that case.

Rebased Amit's patch and included my own 0002 to fix the REINDEX CONCURRENTLY
issue.

-- 
Justin

Commits

  1. Refactor cluster.c to use new routine get_index_isclustered()

  2. Preserve clustered index after rewrites with ALTER TABLE

  3. Preserve replica identity index across ALTER TABLE rewrite

  4. Remove RangeIOData->typiofunc

  5. Preserve pg_index.indisclustered across REINDEX CONCURRENTLY