It begins by defining what data mathematically, the relationship between data, and how all of this into information and wisdom that you want from your database, with a number of interesting examples and warnings. Read the introduction and you'll even understand statistics better. The data and relationships in any database is only ever a subset of the real world only with the attributes and relationships that are important to how the database you need to work. He covers the techniques of the main design databases; is soon to be technical, with code snippets and references to a variety of database theory, but usually an example to understand it all. Details about how to handle numerical data, text and "exotic" data such as multimedia and geographic information, how to encrypt data, and how to check for errors certainly useful, but strangely all of this comes before the explanation of what relational databases are and how they work.