Cmu course is a must watch really
I wonder what are alternatives (video lectures or textual resources) with more hands-on approach implementing database systems.
Otherwise there is surprisingly a lack of information about architecting databases online and you have to go to the source code of SQLite and PostgreSQL. I suspect this is because databases are some of the most complex systems in computer science and involve many trade secrets.
Inspired by this post, I started yet another: https://sqlite.org/draft/howitworks.html