6.3. Transactions, Locking, and Isolation

The final topic in this chapter deals with the important (and hair-raising!) topic of transaction handling.

Transaction handling is a feature of the more powerful database systems in which SQL statements can be grouped into logical chunks. Each chunk is known as a transaction, and the operations it performs are guaranteed to be atomic for the purposes of recovery. According to the ANSI/ISO SQL standard, a transaction begins with the first executable SQL statement and ends when it is explicitly committed or rolled back.