I'll assume you want a properly formatted PDF (or linkable GitHub project) of updated materials on "database internals"—for example, an organized, up-to-date notes/ebook collecting authoritative resources, implementations, diagrams, and code—ready to publish on GitHub.
Go to GitHub and watch (select "Releases only" or "Custom" for issues/prs) these repos: database internals pdf github updated
This repository contains an explaining the inner workings of database systems – from disk structures to distributed consensus. It is designed for: I'll assume you want a properly formatted PDF