There is a section of the Derby Developer's guide entitled "Debugging Deadlocks", see http://db.apache.org/derby/docs/dev/devguide/cdevconcepts50894.html.
This section refers to an internal class in the Derby engine without giving more information about this class, or how you can use it:
"Derby provides a class to help you in this situation, org.apache.derby.diag.LockTable."
At the very least, the manual should include a direct pointer (link) to the Javadoc for that class, located at http://db.apache.org/derby/javadoc/engine/org/apache/derby/diag/LockTable.html.
Ideally, some information should be provided, showing readers how to use this class for debugging, and/or describing how the information in the Javadoc can be utilized. Some links, hints and tips in this regard exist on the following wiki page: http://wiki.apache.org/db-derby/LockDebugging. In essence, the LockTable Javadoc contains most of the hints needed to interpret a deadlock error message or a dump of the lock table (see
DERBY-2817 or the Derby wiki for examples).
The same paragraph in the manual is rounded off with the sentence "For information, see the Derby Server and Administration Guide.". It is not at all clear to the reader what kind of information to look for in the Server and Administration Guide, if such relevant information exists. This reference should either be more specific, or removed.