Systems Analysis and Synthesis

6.5. Transactions

In the embedded SQL example of Section  6.3.3, we saw the use of commit to mark the completion of an event procedure. It was stated that the purpose of commit was to make the procedure atomic . By atomic, we mean that the database has a defined state before the event and a defined state after the event, but its state shouldn’t be inspected during the event. In the context of a DBMS, the change from the before state to the after state is called a transaction. In most cases, ‘transaction’ and ‘event’ are synonymous, but it is possible to imagine events that comprise more than one transaction. Indeed, it wouldn’t matter greatly if the Freeze event of Section  5.7 updated the state of each subject as a separate transaction.

6.5.1. ...