On Fri, May 21, 2021 at 1:30 AM Guillaume Lelarge <guilla...@lelarge.info> wrote: > > >> If so, the >> problem might be that copying the data of the first table creates a >> transaction which blocks creation of the slot for second table copy. > > > I don't understand how a transaction could block the creation of a slot. > Could you explain that to me? >
During the creation of the slot, we need to build the initial snapshot which is used for decoding WAL. Now, to build the initial snapshot, we wait for all running xacts to finish. See functions CreateReplicationSlot() and SnapBuildFindSnapshot(). -- With Regards, Amit Kapila.
