"Architecture of a Database System" by Hellerstein, Stonebraker and Hamilton [1], gives a good overview. The source code and documentation of PostgreSQL is exce

"Architecture of a Database System" by Hellerstein, Stonebraker and Hamilton [1], gives a good overview. The source code and documentation of PostgreSQL is excellent if you want to dive deeper. [1] http://db.cs.berkeley.edu/papers/fntdb07-architecture.pdf http://db.cs.berkeley.edu/papers/fntdb07-architecture.pdf