> Just for my own edification, when auto commit is on, when the driver
> detects that the statement failed and then requests a rollback, how
> does the caller get notified that the statement (and transaction)
> failed? Does the driver then raise its own exception?

Transaction management is transparent. You will get exactly that
exception that was reported by the server. Only if exception happens
during commit or rollback, you will get latter exception.

Best regards,
Roman Rokytskyy