On 2018-10-30 11:51:09 +0900, Michael Paquier wrote: > On Mon, Oct 29, 2018 at 12:13:04PM -0700, Andres Freund wrote: > > I don't think this quite is the problem. ISTM the issue is rather that > > StartupReplicationSlots() *needs* to check whether wal_level > minimal, > > and doesn't. So you can create a slot, shutdown, change wal_level, > > startup. A slot exists but won't work correctly. > > It seems to me that what we are looking for is just to complain at > startup if we find any slot data and if trying to start up with > wal_level = minimal.
Right, we really should just call CheckSlotRequirements() before doing so. I'll make it so, once I'm actually awake and had some coffee. > Er... At the same time, shouldn't RestoreSlotFromDisk() *not* use PANIC > if more slots are found in pg_replslot than max_replication_slots can > handle. A FATAL is fine at startup, PANIC blows up a core file, which > is clearly overdoing it if the goal is to give a recommendation at the > end. I can't get particularly excited about this. I guess we can change it, but I'd only do so in master. Greetings, Andres Freund
