Re: Hints (was Poor performance using CTE)

On Wed, Nov 21, 2012 at 5:42 AM, Kevin Grittner <kgrittn(at)mail(dot)com> wrote:

>
> It's a tough problem. Disguising and not documenting the available
> optimizer hints leads to more reports on where the optimizer should
> be smarter, and has spurred optimizer improvements. ...
> Regarding the above-mentioned benefits we would stand to lose by
> having clear and documented hints, perhaps we could occasionally
> solicit input on where people are finding hints useful to get ideas
> on where we might want to improve the optimizer. As far as worrying
> about people using hints to force a plan which is sub-optimal --
> isn't that getting into nanny mode a bit too much?
>

Toward that end, the hint documentation (which is almost always viewed as
HTML) could be prefaced by a strong suggestion to post performance
questions in this group first, with links to the "subscribe" page and the
"how to report performance problems" FAQ. The hint documentation could even
be minimalistic; suggest to developers that they should post their
problematic queries here before resorting to hints. That would give the
experts an opportunity to provide the normal advice. The correct hint
syntax would be suggested only when all other avenues failed.

Craig James

>
> -Kevin
>