When creating columns of type LONG VARCHAR or LONG VARCHAR FOR BIT DATA, you are not allowed to specify the maximum length of the data. The current wording in the reference manual may be read as that you can set the maximum length, but that you don't have to. We should state that specifying the length is not allowed for these two data types.
From https://bugs.eclipse.org/bugs/show_bug.cgi?id=286206 :
The Derby manual I referred to said "you do not have to specify a maximum
length when creating columns of this type". What they actually meant is "you
cannot specify a maximum length"!