This chapter, and the next chapters, will provide a high-level overview of topics related to database development. These topics will cover the theoretical aspect of relational databases. The first two chapters try to summarize theoretical topics that are seen on a daily basis. Understanding these theoretical concepts will enable the developers to not only come up with clean designs, but also to master relational databases.

This chapter is not restricted to learning PostgreSQL, but covers all relational databases. The topics covered in this chapter include the following:

• Database management systems: Understanding the different database categories enables the developer to utilize the best in each world
• Relational algebra: Understanding relational algebra enables the developers to master the SQL language, especially SQL code rewriting
• Data modeling: Using data modeling techniques leads to better communication