On 11.03.25 11:42, Peter Eisentraut wrote:
Here is an updated patch that works more along those lines. It adds a
pg_upgrade option --update-checksums, which activates the code to
rewrite the checksums. You must specify this option if the source and
target clusters have different checksum settings.
Note that this also works to hypothetically upgrade between future
different checksum versions (hence "--update-*", not "--enable-*").
Also, as the patch is currently written, it is also required to specify
this option to downgrade from checksums to no-checksums. (It will then
write a zero into the checksum place, as it would look if you had never
used checksums.) Also, you can optionally specify this option even if
the checksum settings are the same, then it will recalculate the
checksums. Probably not all of this is useful, but perhaps a subset of
it. Thoughts?
Also, I still don't know what to do about the Windows code path in
copyFile(). We could just not support this feature on Windows? Or
maybe the notionally correct thing to do would be to move that code into
copyFileByRange(). But then we'd need a different default on Windows
and it would require more documentation. I don't know what to do here
and I don't have enough context to make a suggestion. But if we don't
answer this, I don't think we can move ahead with this feature.
I'm not sensing much enthusiasm for this feature or for working out the
remaining problems, so I'm closing this commitfest entry.
