[AccessD] Optimizing query when select part requires acalculation

I stand corrected. Thanks for this.

Arthur

On Thu, Oct 13, 2011 at 4:59 PM, Asger Blond <ab-mi at post3.tele.dk> wrote:

> Arthur,
> You wrote:
> >> Any IN() or NOT IN() expression forces a full table scan,
> >> regardless of the indexes available...
> This is simply not true. If the subquery in an IN clause have a WHERE
> condition on an indexed column then this index will certainly be used in a
> SEEK operation if the index is considered useful for the query optimizer. It
> will be used in exactly the same way as when the statement enclosed in the
> IN clause is run separately.
> Asger
>
>