It is not possible to reuse a single connection better, if we're talking about postgres. You must conduct the transaction over a single connection and you canno

It is not possible to reuse a single connection better, if we're talking about postgres. You must conduct the transaction over a single connection and you cannot mix different transactions simultaneously over a single connection. That's the way postgres wire protocol works. I think that there's some rudimentary async capabilities, but they don't change anything fundamentally. It might be different for some exotic databases, but I don't see any reason why ordinary JDBC driver couldn't reuse single TCP connection for multiple logical JDBC connections in this case.