Re: B-Tree support function number 3 (strxfrm() optimization) - Mailing list pgsql-hackers

On Thu, Aug 7, 2014 at 12:17 PM, Robert Haas <robertmhaas@gmail.com> wrote:
> Gah.  Hit send to soon.  Also, as much as I'd prefer to avoid
> relitigating the absolutely stupid debate about how to expand the
> buffers, this is no good:
>
> +               tss->buflen1 = Max(len1 + 1, tss->buflen1 * 2);
>
> If the first expansion is for a string >512MB and the second string is
> longer than the first, this will exceed MaxAllocSize and error out.

Fair point. I think this problem is already present in a few existing
places, but it shouldn't be. I suggest this remediation:

> +               tss->buflen1 = Max(len1 + 1, Min(tss->buflen1 * 2, (int) MaxAllocSize));

I too would very much prefer to not repeat that debate.  :-)
-- 
Peter Geoghegan