Mihail Nikalayeu <[email protected]> wrote: > On Thu, Apr 9, 2026 at 10:43 AM Antonin Houska <[email protected]> wrote: > > This approach LGTM when it comes to concurrent DDLs. However, consider > > REPACK > > holding ShareUpdateExclusiveLock (SUEL) and VACUUM (w/o VACOPT_SKIP_LOCKED) > > waiting for the same lock. Once REPACK releases its SUEL, VACUUM gets it and > > processes the table, then REPACK finally gets AccessExclusiveLock (AEL) and > > finishes too. > > > One more thing we may prevent from sneaking into that hole is a > > VACUUM. It will not break anything, but will be huge waste of time and > > resources. > > > I thought about that too, I think we may just add some kind of > CheckTableNotInUse in VACUUM after getting the SUEL.
Sure, it's possible, but IMO the principal question is whether REPACK should let VACUUM and DDLs error out, or just let them wait. -- Antonin Houska Web: https://www.cybertec-postgresql.com
