Re: pg_upgrade: Support for upgrading to checksums enabled

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.