Re: [PoC] Improve dead tuple storage for lazy vacuum - Mailing list pgsql-hackers

On Mon, Mar 25, 2024 at 10:13 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
>
> Masahiko Sawada <sawada.mshk@gmail.com> writes:
> > On Mon, Mar 25, 2024 at 1:53 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> >> I think the point here is that if you start with an arbitrary
> >> non-negative shift value, the preceding loop may in fact decrement it
> >> down to something less than zero before exiting, in which case we
> >> would indeed have trouble.  I suspect that the code is making
> >> undocumented assumptions about the possible initial values of shift.
> >> Maybe some Asserts would be good?  Also, if we're effectively assuming
> >> that shift must be exactly zero here, why not let the compiler
> >> hard-code that?
>
> > Sounds like a good solution. I've attached the patch for that.
>
> Personally I'd put the Assert immediately after the loop, because
> it's not related to the "Reserve slot for the value" comment.
> Seems reasonable otherwise.
>

Thanks. Pushed the fix after moving the Assert.


Regards,
--
Masahiko Sawada
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