Let me open with this handbook's positives. It has reasonably useful BNF-like syntaxes for SQL and statements useful to the administration and tuning of SYBASE installations. The author also does a good job detailing the history of SYBASE's growth and development, and the differences between products on the market. Several chapters offer fair introductions to a variety of topics. For a DBA's handbook, I might give this a mediocre two stars.
Stop here if you're a Developer, though, and look for a Developer's Handbook elsewhere, because this book falls short of what it actually claims to be. There's nothing on Transact-SQL, all the add-on statements that SYBASE supports like dateadd(), etc. The programming APIs most developers are likely to use such as OpenClient, is given a cursory example chapter which does little to explain OpenClient's intricacies. Instead, the example (whose C code is in double-spaced Courier type which fills space by having approximately fifteen lines of code per page of code listings) is heavily lifted from SYBASE's own OpenClient example program (only the SQL statement being performed programmatically appears to differ).
Lastly, there's absolutely nothing about Python integration in this book, if that matters to you. But even if it doesn't, the poor typography, numerous typos and grammatical errors, and general lack of new or useful information to anyone already acquainted with SYBASE should be taken as strong signs to spend your documentation dollars elsewhere for a developer's handbook for this RDBMS.