Jordan Tirell wrote:
> I have found that they work fine with non-unique
> paths and use the earliest defined path by default.
I don't use JDB, but from your description of the problem, I expect that
the authors of JDB knew that it selected the earliest defined path (this
is a common result of certain J primitives). I also suspect that they were
trying to dissuade you from relying on this behavior, for two reasons:
(A) It's a bad idea from an application logic point of view,
because adding a new table or column could cause a completely
problems in a completely unrelated part of the code
(if the new table/column becomes the new earliest defined path).
(B) They didn't want to guaruntee this behavior; they want the
freedom to change it in future versions without worrying about
backwards compatibility (which means even if you're careful
never to trigger the trap in (A), you could still get hurt).
This is analogous to the reasons that SELECT * ... is disfavored in the
SQL community.
-Dan
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