Discovering SQL: A Hands-On Guide for Beginners

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Drowning in Data, Dying of Thirst for Knowledge

Information may be the most valuable commodity in the modern world. It can take many different forms: accounting and payroll information, information about customers and orders, scientific and statistical data, graphics, and multimedia, to mention just a few. We are virtually swamped with data, and we cannot (or at least we'd like to think about it this way) afford to lose it. As a society, we produce and consume ever increasing amounts of information, and database management systems were created to help us cope with informational deluge. These days we simply have too much data to keep storing it in file cabinets or cardboard boxes, and the data might come in all shapes and colors (figuratively speaking). The need to store large collections of persistent data safely, and “slice and dice” it efficiently, from different angles, by multiple users, and update it easily when necessary, is critical for every enterprise.

Besides storing the information, which is what electronic files are for, we need to be able to find it when needed and to filter out what is unnecessary and redundant. With the informational deluge brought about by Internet findability, the data formats have exploded, and most data comes unstructured: pictures, sounds, text, and so on. The approach that served us for decades — shredding data according to some predefined taxonomy — gave in to the greater flexibility of unstructured and semistructured data, and all this ...