Re: Simple join optimized badly?

Craig A. James wrote:

>
> Perhaps you scanned past what I wrote a couple paragraphs farther down.
> I'm going to repeat it because it's the KEY POINT I'm trying to make:
>
> Craig James wrote:
>> Now you might argue that function-cost needs to be added to the
>> optimizer's arsenal of tricks. And I'd agree with you: That WOULD be
>> a better solution than hints. But I need my problem solved TODAY, not
>> next year. Hints can help solve problems NOW that can be brought to
>> the PG team's attention later, and in the mean time let me get my
>> application to work.

True enough - but (aside from the fact that hints might take just as
long to get into the development tree as cost-for-functions might take
to write and put in...) there is a nasty side effect to adding hints -
most of the raw material for optimizer improvement disappears (and hence
optimizer improvement stalls)- why? simply that everyone then hints
everything - welcome to the mess that Oracle are in (and seem to be
trying to get out of recently)!

I understand that it is frustrating to not have the feature you need now
- but you could perhaps view it as a necessary part of the community
development process - your need is the driver for optimizer improvement,
and it can take time.

Now ISTM that hints "solve" the problem by removing the need any further
optimizer improvement at all - by making *you* the optimizer. This is
bad for those of us in the DSS world, where most ad-hoc tools do not
provide the ability to add hints.

Cheers

Mark