Horton

Re: ALTER tbl rewrite loses CLUSTER ON index

Michael Paquier <michael@paquier.xyz>

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From: Michael Paquier <michael@paquier.xyz>
To: Justin Pryzby <pryzby@telsasoft.com>
Cc: Alvaro Herrera <alvherre@2ndquadrant.com>, Amit Langote <amitlangote09@gmail.com>, Tom Lane <tgl@sss.pgh.pa.us>, pgsql-hackers@postgresql.org, Justin Pryzby <pryzby@telsasoft.com>
Date: 2020-03-18T02:48:37Z
Lists: pgsql-hackers 
On Tue, Mar 17, 2020 at 11:20:44AM -0500, Justin Pryzby wrote:
> On Tue, Mar 17, 2020 at 02:33:32PM +0900, Michael Paquier wrote:
>> Patch 0002 from Justin does that, I would keep this refactoring as
>> HEAD-only material though, and I don't spot any other code paths in
>> need of patching.
>> 
>> The commit message of patch 0001 is not what you wanted I guess.
> 
> That's what git-am does, and I didn't find any option to make it less
> unreadable.  I guess I should just delete the email body it inserts.

Strange...

Anyway, Tom, Alvaro, are you planning to look at what is proposed on
this thread?  I don't want to step on your toes if that's the case and
it seems to me that the approach taken by the patch is sound, using as
basic fix the addition of an AT_ClusterOn sub-command to the list of
commands to execute when rebuilding the table, ensuring that any
follow-up CLUSTER command will use the correct index.
--
Michael

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