Learning Objectives

By the end of this chapter, you will be able to:

  • Describe the traditional file system approach to managing data.
  • Identify the major problems associated with the file system approach.
  • Explain how a database approach solves these problems.

The File System Approach

Before modern databases, data was often stored in a collection of separate application-specific files. This is known as the file system approach. For example, the accounting department would have its own set of files, and the sales department would have a completely separate set of files.

Problems with the File System Approach

This approach created several major problems for organizations:

  1. Data Redundancy: The same data was often duplicated across many different files. A customer’s address, for example, might exist in the sales file, the marketing file, and the accounting file.

  2. Data Inconsistency: This is a direct result of redundancy. If a customer’s address changed, it might be updated in one file but not the others, leading to conflicting versions of the data.

  3. Data Isolation: Because data was stored in different files in different formats, it was very difficult to access and share data across different applications or departments.

The Database Approach

The database approach was created to solve these problems. It involves storing all of an organization’s data in a single, centralized database. This database is managed by a Database Management System (DBMS), which is a software program that controls how data is stored, accessed, and updated.

Advantages of the Database Approach

  • Reduced Redundancy and Inconsistency: By storing data in only one place, the database approach creates a “single source of truth,” which dramatically reduces data redundancy and inconsistency.
  • Improved Data Sharing: With all data in a central location, it is much easier for different departments to share information.
  • Increased Security: A DBMS provides sophisticated tools for controlling who can access and modify the data.

Summary

The traditional file system approach to data management led to significant problems of data redundancy, inconsistency, and isolation. The modern database approach solves these problems by creating a single, centralized database managed by a DBMS. This ensures that data is consistent, secure, and easily accessible to all parts of the organization.

Key Takeaways

  • The file system approach leads to data redundancy, inconsistency, and isolation.
  • The database approach uses a central database and a DBMS to manage data.
  • The database approach creates a “single source of truth” for the organization.

Discussion Questions

  1. What is the most significant problem with the file system approach? Why?
  2. How does a DBMS help to improve data security?
  3. Provide a real-world example of a problem that could be caused by data inconsistency.