Re: [DOCS] HOT - correct claim about indexes not referencing old line pointers

From: Shubham Khanna <khannashubham1197(at)gmail(dot)com>
To: James Coleman <jtc331(at)gmail(dot)com>
Cc: pgsql-hackers <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: [DOCS] HOT - correct claim about indexes not referencing old line pointers
Date: 2023-12-05 05:22:43
Message-ID: CAHv8RjJ0YgtZpsNi5pXJ8qr4czJf0C1ebh03H9dk+k2GW4E7ow@mail.gmail.com
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On Tue, Dec 5, 2023 at 10:51 AM James Coleman <jtc331(at)gmail(dot)com> wrote:
>
> Hello,
>
> While working on my talk for PGConf.NYC next week I came across this
> bullet in the docs on heap only tuples:
>
> > Old versions of updated rows can be completely removed during normal
> > operation, including SELECTs, instead of requiring periodic vacuum
> > operations. (This is possible because indexes do not reference their page
> > item identifiers.)
>
> But when a HOT update happens the entry in an (logically unchanged)
> index still points to the original heap tid, and that line item is
> updated with a pointer to the new line pointer in the same page.
>
> Assuming I'm understanding this correctly, attached is a patch
> correcting the description.
>
> I have Reviewed the patch. Patch applies neatly without any issues. Documentation build was successful and there was no Spell-check issue also. I did not find any issues. The patch looks >good to me.
>
>Thanks and Regards,
>Shubham Khanna.

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