Introduction to Data Management

An Overview of Data Management
1-4 15873 Tandem Computers Incorporated
Figure 1-2. Network of Systems with a Distributed Database
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Database management systems differ in the way they organize records in the
database. The newest database management system, the relational system, organizes
records in a tabular format. In this format, each file contains only one kind of
record—for instance, only checking account records or only bank employee records.
Thus, all records in a particular file have the same structure and field arrangements,
allowing the file to be viewed as a table where a row is a record and a column is a
collection of field values. Because it can include many different files, a database can
contain multiple types of rows (records).
Easy to use and flexible enough to respond to rapidly growing computer systems, a
relational database is ideal for online transaction processing applications. An example
of such a database appears in Figure 1-3. This database is maintained by office
workers responsible for updating the telephone directory at their plant. The
telephone directory file, or table, contains a row for each employee. Within each row,
individual columns denote such information as the employee’s name, telephone
extension, office number, department number, and immediate manager.