I have done some more tests this morning and using the TOP 1 clause is a sure help in my current query (which is a join between 8 tables).
When I take only parts of my queries, the SELECT MAX is faster.
So, what I conclude is that the TOP 1 may help under precise conditions but not always. We might use it with caution.
Éric Moreau, MCPD, Visual Developer - Visual Basic MVP
Conseiller Principal / Senior Consultant
Moer inc.
http://www.emoreau.com