Date: Wed, 9 Jun 2021 21:35:06 -0500
From: Justin Pryzby <pryzby@telsasoft.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Jeff Davis <pgsql@j-davis.com>, pgsql-hackers@postgresql.org,
	Jacob Champion <pchampion@vmware.com>,
	Heikki Linnakangas <hlinnaka@iki.fi>,
	Ashwin Agrawal <aagrawal@pivotal.io>,
	Ashutosh Sharma <ashu.coek88@gmail.com>,
	Andres Freund <andres@anarazel.de>,
	Robert Haas <robertmhaas@gmail.com>,
	Amit Kapila <amit.kapila16@gmail.com>,
	Alvaro Herrera <alvherre@alvh.no-ip.org>,
	Dilip Kumar <dilipbalaut@gmail.com>
Subject: Re: alter table set TABLE ACCESS METHOD
Message-ID: <20210610023506.GZ16435@telsasoft.com>
References: <20210308010707.GA29832@telsasoft.com>
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 <20210506221943.GS27406@telsasoft.com>
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On Wed, Jun 09, 2021 at 01:47:18PM +0900, Michael Paquier wrote:
> On Tue, Jun 08, 2021 at 05:33:31PM -0700, Jeff Davis wrote:
> > New version attached, with the detoasting code removed. Could use
> > another round of validation/cleanup in case I missed something during
> > the merge.
> 
> This looks rather sane to me, thanks.
> 
>     /* Create the transient table that will receive the re-ordered data */
>     OIDNewHeap = make_new_heap(tableOid, tableSpace,
> +                              accessMethod
> It strikes me that we could extend CLUSTER/VACUUM FULL to support this
> option, in the same vein as TABLESPACE.  Perhaps that's not something to
> implement or have, just wanted to mention it.

It's a good thought.  But remember that that c5b28604 handled REINDEX
(TABLESPACE) but not CLUSTER/VACUUM FULL (TABLESPACE).  You wrote:
https://www.postgresql.org/message-id/YBuWbzoW6W7AaMv0%40paquier.xyz
> Regarding the VACUUM and CLUSTER cases, I am not completely sure if
> going through these for a tablespace case is the best move we can do,
> as ALTER TABLE is able to mix multiple operations and all of them
> require already an AEL to work.  REINDEX was different thanks to the
> case of CONCURRENTLY.  Anyway, as a lot of work has been done here
> already, I would recommend to create new threads about those two
> topics.  I am also closing this patch in the CF app.

In any case, I think we really want to have an ALTER .. SET ACCESS METHOD.
Supporting it also in CLUSTER/VACUUM is an optional, additional feature.

-- 
Justin