Sanne Grinovero OK, then I think we're settled.

And I think I should withdraw my proposal to make the isolation level an enum - the exact meaning of isolation level wouldn't be precise anyway as the levels defined by ANSI SQL-92 suck (the definition is ambiguous especially for MVCC). We can keep relaxed isolation a provider-specific option. I would still love to see a 2LC provider TCK (including multi-threaded stress tests), but that could simply check that the provider is capable of serializable isolation, and does not have to test looser semantics.

Steve Ebersole The question that persists: Is there an option to query the current connection isolation level if this is not set in properties? I haven't seen such method in Dialect.