More than 1 Hint in Select

Question

Hi
Is possible put more than a hint in Select ? How can I do ?

Answer 1

Well, I support what was said by Mark... partially.
Indeed, hints should be avoided whenever possible. However, I wouldn't claim that hinting is something that should be avoided at all cost.
How about ALL_ROWS and FIRST_ROWS hints?
How about DYNAMIC_SAMPLING hint?
Should we avoid using APPEND hint, after all?
In my opinion, we need to understand that:
1. There are hints that have nothing to do with CBO decisions (APPEND, for example). They can't really hurt.
2. There are hints that sometimes help CBO to make better decisions (DYNAMIC_SAMPLING). I wouldn't call them "bad" as well.
3. Hints to change optimizer goal (like FIRST_ROWS, ALL_ROWS) - again, they are harmless if applied properly.
And finally:
4. Hints that force optimizer to use some fixed access path, join method - in other words to restrict optimizer's search space. These ones are surely bad. They should be used very rarely and considered a "path of last resort".
But then again - before applying such hints we must understand the nature of underlying problem, the underlying cause of bad execution plans. If we blindly hint one query, it's very likely that we'll need to hint many other queries as the problem tends to re-appear in many places of application code.
And by the way - Tom uses similar categorization of hints, too:
http://asktom.oracle.com/pls/ask/f?p=4950:8:::::F4950_P8_DISPLAYID:23566649273765#47839217291071
Kind regards.