Interesting stuff, I've recently got interested in databases and did some toy programming related to them, trying to understand how they work.

I just wish the author had gone closer to the nitty gritty details of _how_ the data is actually fetched from the disk. How does Postgres store the data? What do the data files look like, how is the parsing done?

In any case I appreciate the effort. I guess I might have to dive into the source code myself.