06.03.2026 00:01, Andres Freund пишет: > Hi, > > On 2026-03-05 15:38:24 -0500, Andres Freund wrote: >>> On Thu, 5 Mar 2026 at 21:16, Andres Freund <[email protected]> wrote: >>>> >>>> But it does seem like it could be a problem for incremental backup / >>>> walsummarizer? >>> >>> I don't think it is, because that doesn't do calculations for non-main >>> forks, it considers those forks always changed and includes them in >>> full. Or at least, that was the response I got when I raised concerns >>> about the FSM back when the incremental backup feature was being >>> developed [0]. >> >> There's explicit code for ignoring the FSM, but I don't see the same for the >> VM. And that makes sense: VM changes are mostly WAL logged, just not >> completely / generically (i.e. this complaint), whereas FSM changes are not >> WAL logged at all. > > Unfortunately I can confirm that incremental backups end up with an outdated > VM.
That is why pg_probackup still archive VM at whole in incremental (WAL parsing) backup. That is why WAL-G's incremental backup in WAL-parsing mode is (was?) considered unstable. I know the problem for couple of years. Excuse me I didn't write about. I didn't recognize fix could be as simple as registering VM buffers. My bad. I fill so stupid :-( It would be great if it will be fixed in all supported versions. -- regards Yura Sokolov aka funny-falcon
