PostgreSQL makes use of intraoperation parallelism and that is of interest to me (for my undergad final year research project). I would like to know how operations like selection, projection, join, etc are parallelized, but when I tried to look at the source code, I got extremely overwhelmed. Is there a high-level PostgreSQL "map"?
I tried looking for books that discuss and explore the algorithms and implementations used in PostgreSQL, but unfortunately didn't find any. Though feel free to refer me to such a book if you know about one.
If the only option I have is to dig into the source code, how long would it take me to find the information I want? And if any of you have gone through the source code, what advise would you give to me?