Hi, On 2022-11-16 15:37:40 -0800, Peter Geoghegan wrote: > On Wed, Nov 16, 2022 at 3:27 PM Andres Freund <and...@anarazel.de> wrote: > > What are "snapshotConflictHorizon format XIDs"? I guess you mean format in > > the > > sense of having the semantics of snapshotConflictHorizon? > > Yes. That is the only possible way that any recovery conflict ever > works on the REDO side, with the exception of a few > not-very-interesting cases such as DROP TABLESPACE. > > GetConflictingVirtualXIDs() assigns a special meaning to > InvalidTransactionId which is the *opposite* of the special meaning > that snapshotConflictHorizon-based values assign to > InvalidTransactionId. At one point they actually did the same > definition for InvalidTransactionId, but that was changed soon after > hot standby first went in (when we taught btree delete records to not > use ludicrously conservative cutoffs that caused needless conflicts). > > Anyway, worth calling this out directly in these comments IMV. We're > addressing two closely related things that assign opposite meanings to > InvalidTransactionId, which is rather confusing.
It makes sense to call this out, but I'd s/snapshotConflictHorizon format XIDs/cutoff with snapshotConflictHorizon semantics/ or such? Greetings, Andres Freund
