bx-zone.com says :-
Oracle is not about only mastering SQL. I learnt this lesson while writing my certification exam. There is much more to Oracle than practicing SQL queries. I would say Oracle is an institution in itself and if you are thinking of making a career in Oracle especially as a Database administrator (DBA) then knowing Oracle from within is necessary. A DBA must have the architecture of Oracle at his fingertips. He/She must know what system global area and program global areas are in Oracle memory structures, about Backup and recovery of the DB, and about the security capabilities. Topics such as physical database layouts and storage management in which you read about traditional disk space storage and automatic storage management are of utmost importance for an aspiring DBA. High Availability is also a deep topic in which you come across Real Application Clusters, as a DBA you will have to do hardware configuration, software configuration, network configuration, and will have to manage disk storage. The responsibilities of a DBA are big because without him looking after the installed Oracle an entire project may go down and deliverables may get affected. With all such topics to cover I strongly recommend that you read this book Oracle DBA handbook. Even if you aren’t planning to write the DBA certification in the near future, but are working in a DBA role you should go through this book. There are two-fold advantages - 1) You will be well-prepared before you begin your preparation for the DBA certification in the future 2) Your Oracle management skills will improve so much that you will be more productive and efficient at your job. By reading the entire Oracle DBA handbook you will learn certain skills, certain commands, certain shortcuts that even senior DBAs don’t know. At the right moment, you can even teach them the new features, shortcuts and be a hero. When this book containing so much knowledge inside is available at such a big discount then you shouldn’t hesitate to buy it and give up on the chance of being the best DBA.