> > I don't chime in very often, but I do think the refusal to
> > hints into the planner system is fantastically stubborn and 
> > nonsensical.
> What is actually fantastically nonsensical about this is that 
> the issues I outlined about prepared statements would merely 
> become worse if planner hints were used.  Then, you wouldn't 
> only have to worry about plans that were created earlier 
> during the session, you would be faced with plans that were 
> created earlier during the application's development.  In 
> general, the solutions to the prepared statement issues need 
> to effect that the plans are created more often, not less often.

I have yet to see one of our partial Informix hints (where the planner
does it's
usual job only with one path with lowered/elevated costs) fall foul on 
not anticipated change of underlying data.

Thus I don't buy the argument that hints are always bad.
Of course their use should be extremely rare and well thought out.
Most of the time sql tuning involves a concerted effort between the
programmer and a db performance expert, usually resulting in 
rewritten sql or program logic without adding hints.

I can see arguments for hints the dba can set himself centrally on the
but in my experience chances for substantial improvement are very
limited in that case.


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