1. Roundup
Congratulations, you're almost done. Let's quickly revise what you've done throughout this course.
2. How you've transformed the database
You started with a simple table with a lot of redundancy. You might be used to such tables when working with flat files like CSVs or Excel files. Throughout the course, you transformed it step by step into the database schema on the right – only by executing SQL queries. You've defined column data types, added primary keys and foreign keys, and through that, specified relationships between tables. All these measures will guarantee better data consistency and therefore quality. This is especially helpful if you add new data to the database but also makes analyzing the data easier.
3. The database ecosystem
To go further from here, it's useful to look at the bigger picture for a minute. In this course, you've transformed a database. You did that with PostgreSQL, which is also called a "Database Management System", or DBMS. The DBMS and one or more databases together form the "Database System". The DBMS exposes a query interface where you can run ad-hoc analyses and queries with SQL. However, you can also access this interface through other client applications. You could, for example, program a Python script that connects to the database, loads data from it, and visualizes it.
4. The database ecosystem
In the remainder of this course, you'll no longer manipulate data in your database system, but employ some analysis queries on your database. This will be a quick repetition of what you've learned in previous SQL courses such as "Intro to SQL for Data Science", but it will also demonstrate the advantages of having a database instead of a flat file in the first place.
5. Thank you!
For me it's time to say goodbye, thank you for taking this course, and I hope you will soon build your first relational database with the knowledge you've gained here.