e-Commerce Applications Using Oracle8i and Java from Scratch

Managing Transactions

A transaction is the smallest unit of work. Either all the statements that are part of a transaction should be completely successful or none of them should be successful. It uses the concept of all-or-none. When a transaction completes, it is called committed and its changes are applied to the database. When a transaction doesn't complete successfully, it is rolled back. Rolling back a transaction undoes any modification that might have been made by the transaction to the database. Transactions are also used as a unit of recovery. A log is maintained in the database of all the transactions that have occurred against the database so that, if needed, transactions can be rolled back or rolled forward. Rolling back a transaction ...