>the true headache begin when you have this situation:
>where condition1 OR condition2
>both condition1 condition2 that are optimized
>but the engine generates a plan that run across the all table.
>I solve with a UNION, which has zero readability,
>but it can be thousands of times faster

I would be interested to see an example of such command, making usage of the UNION for such approach.

Thanks