On Mon, Jun 26, 2023 at 11:15 AM Drouvot, Bertrand <bertranddrouvot...@gmail.com> wrote: > > On 6/20/23 12:22 PM, Amit Kapila wrote: > > On Mon, Jun 19, 2023 at 9:56 PM Drouvot, Bertrand > > <bertranddrouvot...@gmail.com> wrote: > > >> In such a case (slot valid on the primary but invalidated on the standby) > >> then I think we > >> could drop and recreate the invalidated slot on the standby. > >> > > > > Will it be safe? Because after recreating the slot, it will reserve > > the new WAL location and build the snapshot based on that which might > > miss some important information in the snapshot. For example, to > > update the slot's position with new information from the primary, the > > patch uses pg_logical_replication_slot_advance() which means it will > > process all records and update the snapshot via > > DecodeCommit->SnapBuildCommitTxn(). > > Your concern is that the slot could have been consumed on the standby? > > I mean, if we suppose the "synchronized" slot can't be consumed on the > standby then > drop/recreate such an invalidated slot would be ok? >
That also may not be sufficient because as soon as the slot is invalidated/dropped, the required WAL could be removed on standby. -- With Regards, Amit Kapila.
