On Wed, Oct 20, 2021 at 9:01 PM Kyotaro Horiguchi <horikyota....@gmail.com> wrote: > > lastOverflowedXid is the smallest subxid that possibly exists but > possiblly not known to the standby. So if all top-level transactions > older than lastOverflowedXid end, that means that all the > subtransactions in doubt are known to have been ended.
Thanks for the patch! I verified that it appears to reset lastOverflowedXid properly. I may not be understanding https://github.com/postgres/postgres/blob/dc899146dbf0e1d23fb24155a5155826ddce34c9/src/backend/storage/ipc/procarray.c#L1326-L1327 correctly, but isn't lastOverflowedXid the last subxid for a given top-level XID, so isn't it actually the largest subxid that possibly exists?
