From: Tom Lane <tgl@sss.pgh.pa.us>
To: Robert Haas <robertmhaas@gmail.com>
cc: Pavan Deolasee <pavan.deolasee@gmail.com>, amul sul <sulamul@gmail.com>,
        Amit Kapila <amit.kapila16@gmail.com>,
        Stephen Frost <sfrost@snowman.net>,
        PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] Restrict concurrent update/delete with UPDATE of
 partition key
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Comments: In-reply-to Robert Haas <robertmhaas@gmail.com>
	message dated "Thu, 08 Mar 2018 11:57:05 -0500"
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Date: Thu, 08 Mar 2018 12:03:59 -0500
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Robert Haas <robertmhaas@gmail.com> writes:
> Therefore, the only options are (1) ignore the problem, and let a
> cross-partition update look entirely like a delete+insert, (2) try to
> throw some error in the case where this introduces user-visible
> anomalies that wouldn't be visible otherwise, or (3) revert update
> tuple routing entirely.  I voted for (1), but the consensus was (2).

FWIW, I would also vote for (1), especially if the only way to do (2)
is stuff as outright scary as this.  I would far rather have (3) than
this, because IMO, what we are looking at right now is going to make
the fallout from multixacts look like a pleasant day at the beach.

			regards, tom lane