As a former student of his I can recommend Jeff Erickson’s free online algorithms textbook if you’re looking for more sources. :)

https://jeffe.cs.illinois.edu/teaching/algorithms/

very good books. I also recommend Sedgewick's course on coursera

https://www.redblobgames.com/pathfinding/a-star/introduction.html

Would also strongly recommend the Algorithm Design Manual by Skiena
Used this book during AoC and for prepping for interviews.

When it comes to relational databases, I can’t help thinking that something is missing. They’re used everywhere. There are many different databases: from the small and useful SQLite to the powerful Teradata. But, there are only a few articles that explain how a database works.