Hi,
On 2022-03-25 11:50:48 -0400, Tom Lane wrote:
> Robert Haas <robertmhaas@gmail.com> writes:
> > ... It's not
> > like a 16-bit checksum was state-of-the-art even when we introduced
> > it. We just did it because we had 2 bytes that we could repurpose
> > relatively painlessly, and not any larger number. And that's still the
> > case today, so at least in the short term we will have to choose some
> > other solution to this problem.
>
> Indeed. I propose the attached, which also fixes the unsafe use
> of seek() alongside syswrite(), directly contrary to what "man perlfunc"
> says to do.
That looks reasonable. Although I wonder if we loose something by not testing
the influence of the rest of the block - but I don't really see anything.
The same code also exists in src/bin/pg_basebackup/t/010_pg_basebackup.pl,
which presumably has the same collision risks. Perhaps we should put a
function into Cluster.pm and use it from both?
Greetings,
Andres Freund
