The book should...
- Require no prior knowledge.
- Be 200 pages or less.
- Contain only the most most important elements of PL/SQL.
- Function as a survival guide.
I write Oracle certification study guides. By design, I make them as concise as possible in order to have a final product that can be used to help direct certification candidates while they prepare for the test and still be short enough to re-read a day or two before the exam date as a review. My guide for the OCA PL/SQL exam, Study Guide for 1Z0-144: Oracle Database 11g: Program with PL/SQL, at 178 pages is not far from the supplied maximum. However, by no means could the topics covered on the 1Z0-144 exam be considered '...the most most important elements of PL/SQL'. They are simply a reasonable set of the basic knowledge required to develop in PL/SQL.
In addition, even on the relatively focused subset of PL/SQL covered by the exam, the guide does not go into the depth that these subjects require for complete understanding. Oracle professionals that have used PL/SQL will be able to put the information into context. People new to PL/SQL will need to supplement the guide with other sources to really understand the material covered by the exam. That is why I provide links to more details on the 1Z0-144 page on my companion website.
From this I can state with great confidence that there is no way that a 200 page book can simultaneously cover all of the important aspects of PL/SQL and be something that is written at a level that would be useful for someone new to the language.
One book that I consider to be an excellent A to Z resource for people just learning PL/SQL is Oracle PL/SQL Programming by Steven Feuerstein and Bill Pribyl. It meets all of the required elements except for the page limit. At 1,232 pages, it is just over six times the maximum requested. No reason was supplied for the 200-page restriction. Whatever the reason, if someone wants to start a career with Oracle as a PL/SQL developer, my advice would be to use the best resources available to learn the language rather than setting an arbitrary restriction on the size of that resource.