>
>OK - I see what you mean. Is there a database that really joins more than 2 tables at a time?

Yes. SQL Server can do this.

>Or is that what optimization really implies, anyway?

Rushmore optimization uses the index tags available.

>
>I still don't quite get Rushmore, though.
>I find that if I do a basic parent-child-grandchild join like the example with indexes on A.id, B.id, B.id_A, C.id_B, I get Rushmore optimization of None on all tables, but it says it joins on the indexes given.
>Also, according to the docs, if I index on UPPER(char_field) the following should be fully optimizable, but I only get partial optimization.

SELECT * FROM test WHERE UPPER(char_field) = "SOMETHING"

>Does this make sense to you?

Look at the Rushmore KB article on my web site. It may help you out.