Starts a SQL transaction.

A transaction can run for a maximum of 24 hours. A transaction is terminated and rolled back automatically after 24 hours.

A transaction times out if no calls use its transaction ID in three minutes. If a transaction times out before it's committed, it's rolled back automatically.

DDL statements inside a transaction cause an implicit commit. We recommend that you run each DDL statement in a separate ExecuteStatement call with continueAfterTimeout enabled.