public inbox for [email protected]  

help / color / mirror / Atom feed

From: Tom Lane <[email protected]>
To: David Rowley <[email protected]>
Cc: Andrew Dunstan <[email protected]>
Cc: Richard Guo <[email protected]>
Cc: jian he <[email protected]>
Cc: PostgreSQL Hackers <[email protected]>
Subject: Re: Revert: Remove useless self-joins *and* -DREALLOCATE_BITMAPSETS make server crash, regress test fail.
Date: Tue, 07 May 2024 18:40:16 -0400
Message-ID: <[email protected]> (raw)
In-Reply-To: <CAApHDvoR9cXHb_+j7j8=zBty35B8z22SX51cZN7ZRf+QTPJ1fA@mail.gmail.com>
References: <CACJufxFVQmr4=JWHAOSLuKA5Zy9H26nY6tVrRFBOekHoALyCkQ@mail.gmail.com>
	<CAApHDvpBMSGhXVeFdw_qmjPqU5yHvJJ7k0z7kD069EC4di2Pag@mail.gmail.com>
	<CAMbWs4-iYKxrMs8kj+49gVA4X1_=PYAaw5HL_3g_yVXpAHzYww@mail.gmail.com>
	<[email protected]>
	<[email protected]>
	<CAApHDvoR9cXHb_+j7j8=zBty35B8z22SX51cZN7ZRf+QTPJ1fA@mail.gmail.com>

David Rowley <[email protected]> writes:
> On Wed, 8 May 2024 at 06:20, Tom Lane <[email protected]> wrote:
>> I find that Richard's proposed fix makes the core regression tests
>> pass, but we still fail check-world.  So I'm afraid we need something
>> more aggressive, like the attached which makes make_restrictinfo
>> copy all its input bitmapsets.  Without that, we still have sharing
>> of bitmapsets across different RestrictInfos, which seems pretty
>> scary given what we now see about the effects of 00b41463c.  This
>> seems annoyingly expensive, but maybe there's little choice?

> We could make the policy copy-on-modify.  If you put bms_copy around
> the bms_del_member() calls in remove_rel_from_query(), does it pass
> then?

Didn't test, but that route seems awfully invasive and fragile: how
will we find all the places to modify, or ensure that the policy
is followed by future patches?

			regards, tom lane

view thread (2+ messages)

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
  Subject: Re: Revert: Remove useless self-joins *and* -DREALLOCATE_BITMAPSETS make server crash, regress test fail.
  In-Reply-To: <[email protected]>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox