From: Drouvot, Bertrand <bdrouvot@amazon.com>
To: Dilip Kumar <dilipbalaut@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: [BUG] Failed Assertion in ReorderBufferChangeMemoryUpdate()
Date: Mon, 6 Sep 2021 17:24:23 +0200
Message-ID: <73dcd904-cfee-21f2-d363-317cd517cb00@amazon.com> (raw)
In-Reply-To: <CAFiTN-uoTz0bUtOoZxJcB7kPt9xMrKsDATTXoJfktJtPOfC_bw@mail.gmail.com>
References: <92b0ee65-b8bd-e42d-c082-4f3f4bf12d34@amazon.com>
<CAA4eK1LfzPdTO73vW2qUkJeB1k1iL04rmqVJseBbF5qRAonmiw@mail.gmail.com>
<CAFiTN-uoTz0bUtOoZxJcB7kPt9xMrKsDATTXoJfktJtPOfC_bw@mail.gmail.com>
Hi,
On 9/6/21 1:54 PM, Dilip Kumar wrote:
>
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>
> On Mon, Sep 6, 2021 at 4:04 PM Amit Kapila <amit.kapila16@gmail.com
> <mailto:amit.kapila16@gmail.com>> wrote:
>
> On Fri, Aug 13, 2021 at 3:15 PM Drouvot, Bertrand
> <bdrouvot@amazon.com <mailto:bdrouvot@amazon.com>> wrote:
> >
> >
> > Please find attached a patch proposal to avoid the failed
> assertion (by ensuring that ReorderBufferChangeMemoryUpdate()
> being triggered with "addition" set to false in
> ReorderBufferToastReplace() is done after the elog(ERROR,)).
> >
>
> The error can occur at multiple places (like via palloc or various
> other places) between the first time we subtract the change_size and
> add it back after the change is re-computed. I think the correct fix
> would be that in the beginning we just compute the change_size by
> ReorderBufferChangeSize and then after re-computing the change, we
> just subtract the old change_size and add the new change_size. What do
> you think?
>
>
> Yeah, that seems more logical to me.
Thanks for your feedback!
That seems indeed more logical, so I see 3 options to do so:
1) Add a new API say ReorderBufferChangeMemorySubstractSize() (with a
Size as one parameter) and make use of it in ReorderBufferToastReplace()
2) Add a new "Size" parameter to ReorderBufferChangeMemoryUpdate(), so
that if this parameter is > 0 then it would be used instead of "sz =
ReorderBufferChangeSize(change)"
3) Do the substraction directly into ReorderBufferToastReplace()
without any API
I'm inclined to go for option 2), what do you think?
Thanks
Bertrand
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To: pgsql-hackers@postgresql.org
Cc: bdrouvot@amazon.com, dilipbalaut@gmail.com, amit.kapila16@gmail.com, pgsql-hackers@lists.postgresql.org
Subject: Re: [BUG] Failed Assertion in ReorderBufferChangeMemoryUpdate()
In-Reply-To: <73dcd904-cfee-21f2-d363-317cd517cb00@amazon.com>
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