Re: Enable data checksums by default

On 08.08.24 19:42, Robert Haas wrote:
>> I'm thinking pg_upgrade could have a mode where it adds the
>> checksum during the upgrade as it copies the files (essentially a subset
>> of pg_checksums). I think that would be useful for that middle tier of
>> users who just want a good default experience.
> That would be very nice.

Here is a demo patch for that. It turned out to be quite simple.

I wrote above about a separate mode for that (like
--copy-and-make-adjustments), but it was just as easy to stick it into
the existing --copy mode.

It would be useful to check what the performance overhead of this is
versus a copy that does not have to make adjustments. I expect it's
very little.

A drawback is that as written this does not work on Windows, because
Windows uses a different code path in copyFile(). I don't know the
reasons for that. But it would need to be figured out.