Hi Ron, > On Oct 29, 2023, at 16:38, Peter J. Holzer <hjp-pgsql@xxxxxx> wrote: > And this is where it would break down. The modifications can't be > applied to the replica any more because the replica now contains > checksums and the modifications don't. In the best case the replica > would catch the discrepancy and refuse to apply the modifications which > would lead to the loss of these modifications. In the worst case it > would apply them anyway causing severe data corruption. ... > Not just the file headers. Every single data block. > > (Ok, it looks like the space for the checksum is reserved even if > checksums aren't enabled[1]. So at least pg_checksums doesn't have to > move data around to enable them. But overwriting a page with a checksum > with one without one would still be bad.) Those are the kind of answers and insights I was looking for. Thank you very much. Ok, I will do a reinit then. Cheers Paul
