I thought that autocommit simply wraps each SQL statement in its own transaction? Wouldn't a good programming practice, be to ensure that everything that is supposed to be atomic, occur in a single, possibly large, SQL statement anyways?
The performance savings comes from the roundtrip latency of the BEGIN TRANSACTION / COMMIT packets.
"Wouldn't a good programming practice, be to ensure that everything that is supposed to be atomic, occur in a single, possibly large, SQL statement anyways?"