Re: Bug in MultiXact replay compat logic for older minor version after crash-recovery

[Andrey Borodin]

> On 20 Mar 2026, at 18:14, Heikki Linnakangas <hlinn...@iki.fi> wrote:
> 
> Zeroing the page again is dangerous because the CREATE_ID records can be out 
> of order. The page might already contain some later multixids, and zeroing 
> will overwrite them.

I see only cases when it's not a problem: we zeroed page, did not flush it, 
thus did not extend the file, crashed, tested FS, zeroed page once more, 
overwrote again by replaying WAL, no big deal.
We should never zero a page with offsets, that will not be replayed by WAL.

If the page was persisted, even partially, we will read it from disk without 
zeroing out.


Best regards, Andrey Borodin.