[nitwit005]

That's less a SQL issue, than a general issue with attempting to optimize based off of heuristics. Generally when "hints" are supported that's what'll happen every time (baring the hint not being executable).

But, remember that a lot of users wanting to query things aren't going to be app developers. They'll be wanting to do a one off query or run some report. You'll tend to need an optimizer no matter what.

[ulrikrasmussen]

That's true, and you probably want both. You want a general purpose query planner for any user-generated one-off queries, but for the hot application code paths where you execute the same fixed queries again and again, you may be interested in stronger guarantees about your run time complexity.