On Mon, Apr 1, 2024 at 5:54 AM Alexander Korotkov <aekorotkov@gmail.com> wrote: > > > 9. To me the following query blocks even though I didn't mention timeout. > > CALL pg_wal_replay_wait('0/fffffff'); > > If your primary server is freshly initialized, you need to do quite > data modifications to reach this LSN.
Right, but why pg_wal_replay_wait blocks without a timeout? It must return an error saying it can't reach the target LSN, no?
How can replica know this? It doesn't look feasible to distinguish this situation from the situation when connection between primary and replica became slow. I'd keep this simple. We have pg_sleep_for() which waits for the specified time whatever it is. And we have pg_wal_replay_wait() waits till replay lsn grows to the target whatever it is. It's up to the user to specify the correct value.
