Although you can use a database to organize both small and large amounts of information, its true power becomes apparent when you need to manage a substantial volume of data. If, for example, you have a small amount of data to deal with, you can easily manipulate and search it manually; however, as the volume of information increases, performing a manual search becomes both tedious and costly. Consider a filing cabinet containing 20 files versus one containing 20 million files—locating a single file in the first cabinet takes a matter of minutes, whereas locating a single file in the second cabinet is well nigh impossible (given efficiency constraints).

In such situations, an electronic database management system (DBMS) can substantially simplify your work. Not only does such a system take up less physical space than its traditional paper-based counterpart, but it also comes with tools that assist you in organizing your data and simplifying information retrieval and modification. Built-in indexing makes it possible to locate information rapidly and efficiently, while automated processes ensure that data is always stored and cross-referenced in a consistent, error-free manner. A database also offers portability and compatibility (once the data is organized and stored in a database, it can be extracted and displayed in any manner you choose), and it provides a centralized storage location for important information.

A relational database management system (RDBMS) takes things one step further by creating relationships among the tables that make up a database. These relationships can then be used to combine data from multiple tables in various ways, allowing a user to view the same data from various perspectives and then use this enhanced vision to make better (read: more efficient and cost-effective) business decisions. By creating links among related pieces of information, an RDBMS thus not only makes it possible to store information more efficiently (by removing redundancies and repetition), but it also brings to the fore hitherto undiscovered relationships among disparate segments of data and permits efficient exploitation of those relationships.

Remember: this is chapter one of MySQL: The Complete Reference, by Vikram Vaswani (McGraw-Hill/Osborne, ISBN 0-07-222477-0, 2004). Vikram is the founder of Melonfire, and has had numerous articles featured on Dev Shed. Buy this book now.