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
Date: 2020-04-02T07:39:58Z
Lists: pgsql-hackers 
On Thu, Apr 02, 2020 at 04:24:03PM +0900, Michael Paquier wrote:
> On Thu, Apr 02, 2020 at 01:52:09AM -0500, Justin Pryzby wrote:
>> Sounds right.  Or else get_index_isclustered() could be redefined to take a
>> boolean "do_elog" flag, and if syscache fails and that's false, then return
>> false instead of ERROR.
> 
> Not sure if that's completely right to do either.  For one, it is not
> consistent with the surroundings as of lsyscache.c.

Actually, we do have some missing_ok flags lying around already in
lsyscache.c, so it would be much more consistent to use that name that
instead of the do_elog you are suggesting.  Could you update the
patch to reflect that?
--
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