Which readJournal plugin should I use with inmem journal plugin?
let readJournal = mailbox.System.ReadJournalFor<????>(SqlReadJournal.Identifier)
I know for Akka, there is InMemoryReadJournal...
currently there is no Akka.Persistence.Query support for the in-memory journal but one of our contributors offered to start working on it now. I'll update my answer here when we ship something.
I'm also reviewing an Akka.Persistence.Query impl for our Sqlite implementation right now, which offers an in-memory version: https://github.com/akkadotnet/akka.net/pull/6359