Date: Thu, 29 Feb 2024 08:51:31 -0600
From: Justin Pryzby <pryzby@telsasoft.com>
To: Michael Paquier <michael@paquier.xyz>
Cc: Peter Eisentraut <peter@eisentraut.org>,
	Soumyadeep Chakraborty <soumyadeep2007@gmail.com>,
	Zhihong Yu <zyu@yugabyte.com>, pgsql-hackers@postgresql.org,
	Ashwin Agrawal <ashwinstar@gmail.com>, vanjared@vmware.com
Subject: Re: ALTER TABLE SET ACCESS METHOD on partitioned tables
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On Wed, Feb 28, 2024 at 05:08:49PM +0900, Michael Paquier wrote:
> On Wed, Feb 21, 2024 at 08:46:48AM +0100, Peter Eisentraut wrote:
> > Yes, I think most people agreed that that would be the preferred behavior.
> 
> Challenge accepted.  As of the patch attached.

Thanks for picking it up.  I find it pretty hard to switch back to
put the needed effort into a patch after a long period.

> I have implemented that so as we keep the default, historical
> behavior: if pg_class.relam is 0 for a partitioned table, use the AM
> defined by default_table_access_method.  The patch only adds a path to
> switch to a different AM than the GUC when creating a new partition if
> and only if a partitioned table has been manipulated with ALTER TABLE
> SET ACCESS METHOD to update its AM to something else than the GUC.
> Similarly to tablespaces, CREATE TABLE USING is *not* supported for
> partitioned tables, same behavior as previously.

This patch allows resetting relam=0 by running ALTER TABLE SET AM to the
same value as the GUC.  Maybe it'd be better to have an explicit SET
DEFAULT (as in b9424d01 and 4f622503).

-- 
Justin