There's an edX MOOC of a similar title that people here may also may be interested in: https://www.edx.org/course/hacking-postgresql-data-access-me...
From my limited experience diving into the Postgres source code, it's really a treat. Everything is very clearly written and documented. It's pretty easy to read the source code to get an understanding of how components of Postgres work under the hood.
What a gem, thank u :)
Interesting, but shouldn't this be labeled 2007?
It's a shame you can't easily add an extensions to most hosted postgres solutions. I hacked on the postgres ltree extension [1] recently, and was amazed at how easy it is to extend functionality of the database, add new types/operators/etc. I think if they were a bit more accessible we'd see them much more. You can even write them in go [2]
[1] https://github.com/postgres/postgres/tree/master/contrib/ltr...
[2] https://github.com/microo8/plgo