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From: Tom Lane <tgl@sss.pgh.pa.us>
To: Pavan Deolasee <pavan.deolasee@gmail.com>
Cc: amul sul <sulamul@gmail.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>
Cc: Stephen Frost <sfrost@snowman.net>
Cc: Robert Haas <robertmhaas@gmail.com>
Cc: PostgreSQL-development <pgsql-hackers@postgresql.org>
Subject: Re: [HACKERS] Restrict concurrent update/delete with UPDATE of partition key
Date: Thu, 08 Mar 2018 10:07:15 -0500
Message-ID: <10896.1520521635@sss.pgh.pa.us> (raw)
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Pavan Deolasee <pavan.deolasee@gmail.com> writes:
> I am actually very surprised that 0001-Invalidate-ip_blkid-v5.patch does
> not do anything to deal with the fact that t_ctid may no longer point to
> itself to mark end of the chain. I just can't see how that would work.
> ...
> I am actually worried that we're tinkering with ip_blkid to handle one
> corner case of detecting partition key update. This is going to change
> on-disk format and probably need more careful attention.

You know, either one of those alone would be scary as hell.  Both in
one patch seem to me to be sufficient reason to reject it outright.
Not only will it be an unending source of bugs, but it's chewing up
far too much of what few remaining degrees-of-freedom we have in the
on-disk format ... for a single purpose that hasn't even been sold as
something we have to have.

Find another way.

			regards, tom lane




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