I just finished <i>Database in Depth</i>. :-) It is short and readable. It&#x27;s targeted to working database programmers with a few years of SQL already. I learned a bit, but it was a bit of a bait-and-switch: the book is really a polemic about why SQL is not relational enough and people should use the author&#x27;s own Tutorial D. Every page belabors that point. More examples are written in Tutorial D than SQL. I was hoping for some math &amp; theory, and there was some theory, but there was little effort to connect it to SQL except to show SQL&#x27;s shortcomings. For instance I never once saw the term &quot;outer join&quot; (because Date wants to forbid NULLs). If you are interested in database theory and trying new things, it might be very interesting. If you are a working programmer who wants to solidify the foundations, there are probably better choices (I hope).