I'm using this as a revision aid for exam 1Z0-147 which I'm taking in a week's time. I'm still reading it, and have found a lot of the content useful so far, but whilst struggling through chapter 7 (collections) I felt compelled to take a second to complain about how badly written and just plain wrong some of it is. There's a lot of repetition, and in places it looks like text or code examples are copied-and-pasted and not changed to reflect their new subject.
e.g
p.225
"Nested Tables"
"Like varrays, nested tables are single-dimensional structures of Oracle 11g SQL or PL/SQL datatypes. You can use them table [sic], record, and object definitions and access them in SQL and PL/SQL. You can also use nested tables in table, record, and object definitions. They are accessible in both SQL and PL/SQL."
I had a look on the Osborne web site but couldn't find any sort of errata anywhere.