Decision Support Systems

The majority of database applications process many small concurrent update transactions. A bank’s automated teller machine (ATM) system, which must allow for thousands of withdrawal, deposit and transfer transactions to happen concurrently, is a typical example of such an application. This type of processing is known as online transaction processing (OLTP), and databases used to support such processing need to meet the strict ACID properties of transaction processing (see Chapter 8). OLTP is often measured in terms of transaction throughput: the number of committed transactions per second.