On Thu, Feb 8, 2024, at 12:04 AM, Hayato Kuroda (Fujitsu) wrote: > > > Remember the target server was a standby (read only access). I don't expect an > application trying to modify it; unless it is a buggy application. > > > > What if the client modifies the data just after the promotion? > Naively considered, all the changes can be accepted, but are there any issues?
If someone modifies data after promotion, fine; she has to deal with conflicts, if any. IMO it is solved adding one or two sentences in the documentation. > > > Regarding > GUCs, almost all of them is PGC_POSTMASTER (so it cannot be modified unless > the > server is restarted). The ones that are not PGC_POSTMASTER, does not affect > the > pg_createsubscriber execution [1]. > > > > IIUC, primary_conninfo and primary_slot_name is PGC_SIGHUP. Ditto. > > > I'm just pointing out that this case is a different from pg_upgrade (from > which > this idea was taken). I'm not saying that's a bad idea. I'm just arguing that > you might be preventing some access read only access (monitoring) when it is > perfectly fine to connect to the database and execute queries. As I said > before, the current UI allows anyone to setup the standby to accept only local > connections. Of course, it is an extra step but it is possible. However, once > you apply v16-0007, there is no option but use only local connection during > the > transformation. Is it an acceptable limitation? > > > > My remained concern is written above. If they do not problematic we may not > have > to restrict them for now. At that time, changes > > 1) overwriting a port number, > 2) setting listen_addresses = '' It can be implemented later if people are excited by it. > are not needed, right? IIUC inconsistency of -P may be still problematic. I still think we shouldn't have only the transformed primary_conninfo as option. > > > pglogical_create_subscriber does nothing [2][3]. > > > > Oh, thanks. > Just to confirm - pglogical set shared_preload_libraries to '', should we > follow or not? The in-core logical replication does not require any library to be loaded. -- Euler Taveira EDB https://www.enterprisedb.com/