>>Nadya,
>>
>>I don't think merely changing your index expression will solve your problem. Your REPLACE statement will need to be modified in a similar manner. Even then, I'm not sure if it will be optimized.
>
>Right, the REPLACE statement should be changed as well. Why do you think, it would not be Rushmore optimizable? Do you remember, NVL in index expression does automatically turn expression to be non-optimizable?
I would say NVL() isn't "implicitly" R.Optimizable (like "=", "inlist()", etc.), but if the expression on the left exactly matches the index expression, that should be no problem.
An index, and a comparison, on a compound expression, is about the most efficient you can get, since it will only select few records.
Hilmar.
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)