Re: Storing computed values

On Mon, Apr 21, 2008 at 11:19 AM, Colin Wetherbee <cww(at)denterprises(dot)org> wrote:

> My impression of functional indexes is that they're useful mostly in WHERE
> queries, like the following.
>
> SELECT foo, bar, baz FROM some_table WHERE lower(foo) = 'qux';
>
> In this case, the index would be created on lower(foo).
>
> How would I get the value of the functional index out of the index in my
> case?

If this is the case, and you use Natural Foreign Keys, you only need
to select from your foo table:

SELECT Connect( location1, location2)
FROM Foo
WHERE location1 = ...
OR location2 = ...
OR connect(location1,location2) = ...; --this is where the
functional index would be useful

--
Regards,
Richard Broersma Jr.