Hi Mike
I have just succeeded to reproduce the problem on another customer site on ASE 15.7 SP60. See the output of "sp_options show" attached. You mentioned that you receive different results in your tests - could you share some details?
The index scan appears so expensive because the optimizer doesn't recognize the first condition and therefore assumes that a full index scan will be required, which is expensive. If I omit the second, always false condition then an index scan on item_number is used and the query returns very fast (4 LIO), as expected.
Also, if I replace the always false condition with another false condition related to the indexed column, such as " and packages.item_number = -1" (there are no such records for sure), then the optimizer recognizes both conditions, applies an OR optimization strategy and the query returns very fast.
Thanks
Leonid Gvirtz