Fig. 7.1.6 Soon disk storage replaced magnetic tape files.

Enter the DBMS

Applications were built with the aid of software called a database management system—
a DBMS. The DBMS allowed the application programmer to focus on the logic of
processing. The DBMS focused on the placement and accessing of data stored on the
disk.

It wasn’t long after the DBMS appeared that it was recognized that since data could be
accessed directly, rather than sequentially, a new type of application could be built. The
new application that could be built was the online transaction processing application.

Fig. 7.1.7 shows the online transaction processing application.

Chapter 7.1: The Operational Environment: A Short History