DBMS is an important subject when it comes to managing databases. Here’s a list of books I would recommend if you wish to learn DBMS.
Database Management Systems by Raghu Ramakrishnan
1. Database system concepts by Abraham Silberschatz
The best book I've ever read is by "G&G": Data Modeling Essentials, 3rd Edition, by Graeme Simsion and Graham Witt. It's well-written, practical, and full of excellent examples.
I agree that anything by Chris Date is top-notch, but his books are heavy on the mathematical theory behind RDBMS design (not that this is a bad thing).