My DB use has been limited to simple tasks, and I've never had the chance/displeasure of working with a proper RDBMS. However, inspired by this post, I went and dug up my college DB class book. I don't remember making it too far into the book when I took the class, but looking at it now it does cover a huge range of quite interesting topics. I'm not going to make any recommendations, however, because I just don't know enough about the topic. I just wanted to say that I'm glad that I picked up the book again, and that I'm looking forward to learning some more about advanced SQL and DB internals. FWIW, the book we used is "Database Management Systems" by Ramakrishnan and Gehrke, published by McGraw Hill.