On Mon, May 13, 2024 at 03:53:08PM -0400, Robert Haas wrote: > On Sun, May 12, 2024 at 7:29 PM Noah Misch <n...@leadboat.com> wrote: > > - [consequences limited to transient failure] Since a PROC_IN_VACUUM > > backend's > > xmin does not stop pruning, an MVCC scan in that backend can find zero > > tuples when one is live. This is like what all backends got in the days > > of > > SnapshotNow catalog scans. See the pgbench test suite addition. (Perhaps > > the fix is to make VACUUM do its MVCC scans outside of PROC_IN_VACUUM, > > setting that flag later and unsetting it earlier.) > > Are you saying that this is a problem already, or that the patch > causes it to start happening? If it's the former, that's horrible.
The former.