The database design and modeling are one of those topics which rarely get the attention they deserve, especially at the start of the project, but once things have gone out of hand, then everybody talks about them. Comments like - this database is designed poorly, the schema is not performing well, you cannot add a new column easily, etc. becomes very common. The most problem with database design is that it is mainly done by application developers like Java or C++ developer who knows SQL, but they are not the expert on how to design tables and schema. The Database admins or DBAs know database and SQL better than application programmers, but they mostly focus on the admin part of the database, preferably on application part like designing tables and relations between them, which is left to the application developer.