OK, I go to invite you to think.

Suppose that:

We have the most powerfull optimizer and a well-designed database (with a
correct collection of indexes), as you are saying. Still when the optimizer
be a wonderfull decisions tool, some people like to force it in some cases.
This is essencial for an opened database development where the developer can
choose too.

Then, TGRS concept suggests rapid actions inside the code, forcing the
optimizer some times could be a good idea. For me, plans in triggers should
be fixed.

Regards
Dnny

"Helen Borrie" <helebor@...> escribi� en el mensaje
news:5.1.0.14.2.20020522205639.07462700@......

> At 11:36 AM 22-05-02 +0200, Mirza wrote:
> >Helo,
> >
> >Is it really possible for any optimizer to make (at least almost) perfect
> >plan for every query?
>
> Probably not; but at least you can influence the IB optimizer's "good

hit"

> rate by providing a well-designed, well-coordinated collection of indexes
> for it to choose from. From observations over several years in support
> lists, bad optimizer plans are the outcome of poor database design and

lack

> of consideration of contradictory indexing - typically, where a database
> has been ported from Access or Paradox with its indexes simply replicated.
>
> You've seen the comments: "If you're lucky, you'll get a good plan out of
> the optimizer." Yep, it's true: and the better your design, the luckier
> you get.
>
> cheers,
> Helen
>
> All for Open and Open for All
> Firebird Open SQL Database 7 http://firebirdsql.org 7
> http://users.tpg.com.au/helebor/
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