Previous chapters covered query tasks. This chapter dealt with technique - the technique of creating an orderly data layout using multiple tables. This skill takes practice. Expect to redesign your first table layout many times as you improve it.
Good data layout can make your job easier. Bad data layout can make queries a nightmare. As you create your first real-world tables, you will soon learn to identify good and bad data designs. Continually review your table structures. Refer to this chapter again for ideas. Don't be afraid to redesign everything. Redesign is hard, but when it is done properly, queries are much easier to craft.
Relational databases excel in their ability to relate and compare data. Tables can be joined and analyzed in ways never anticipated. With good data layout and the power of SQL, you can retrieve an unlimited amount of information from your database.