Hi, On 2019-04-12 23:34:02 +0530, Amit Khandekar wrote: > I tried to see if I can quickly understand what's going on. > > Here, master wal_level is hot_standby, not logical, though slave > wal_level is logical.
Oh, that's well diagnosed. Cool. Also nicely tested - this'd be ugly in production. I assume the problem isn't present if you set the primary to wal_level = logical? > Not sure why this is happening. On slave, wal_level is logical, so > logical records should have tuple data. Not sure what does that have > to do with wal_level of master. Everything should be there on slave > after it replays the inserts; and also slave wal_level is logical. The standby doesn't write its own WAL, only primaries do. I thought we forbade running with wal_level=logical on a standby, when the primary is only set to replica. But that's not what we do, see CheckRequiredParameterValues(). I've not yet thought this through, but I think we'll have to somehow error out in this case. I guess we could just check at the start of decoding what ControlFile->wal_level is set to, and then raise an error in decode.c when we pass an XLOG_PARAMETER_CHANGE record that sets wal_level to something lower? Could you try to implement that? Greetings, Andres Freund
