Introduction to Relational Databases (RDBMS)

A relational database organizes data into tables that can be linked—or related—based on data common to each. By storing your business data in a relational database, you can retrieve and analyze the data to make important business decisions.

There are many companies that offer relational database systems and, regardless of which one you use, they all share a common set of characteristics that you must be familiar with before you can move on to more advanced operations with databases. In this module, you will learn some basic relational database concepts and how to diagram and describe the relationships between tables in a database. You will also learn the different deployment topologies and architectures that are commonly used, who the typical users of databases are, and some of the features and benefits of some common relational database management systems including Db2, MySQL, and PostgreSQL.

In this module, you will learn how to use a RDBMS GUI or web interface and SQL statements to create and manage the tables in a relational database and populate them with data. You will also learn how to employ some database design techniques that help improve the integrity of your data and the performance of your queries, including the use of Primary and Foreign keys to define relationships, indexes, normalization, and relational model constraints.

MySQL and PostreSQL are two common RDBMS tools for creating and managing relational databases. Both are free and open-source, have download/install and cloud versions, and offer both command-line and desktop and/or web interface options. In this module, you will learn the basics of creating databases and tables, defining keys and constraints in tables, and loading a database with data using MySQL and PostgreSQL. You will also learn how to define views in PostgreSQL to limit access to sensitive data and simplify data retrieval.