Transaction Processing Concepts Goals: Understand the basic properties of a transaction and learn the concepts underlying transaction processing as well as the concurrent executions of transactions.

Hence a transaction, at the simplest level, can be defined as an event involv ing the action of one entity on another. The word ex change is often used to characterize a transaction.

Evolution of Transaction Processing Systems The basic components of a transaction processing system can be found in single user systems. The evolution of these systems provides a convenient …

Durability The effect of a committed transaction will not be lost So data must be on stable storage before commit Usually done with a log (or be forced before commit

Transaction Codes (TC) consist of three digits. They are used to identify a transaction being processed and to maintain a history of actions posted to a taxpayer’s account on the Master File.

Atomicity: A transaction is an atomic unit of processing; it is either performed in its entirety or not performed at all. Consistency preservation: A correct execution of the transaction must take the …

Database System Concepts, 6th Ed. A transaction is a unit of program execution that accesses and possibly updates various data items.