Re: unexpected merge cartesian join

<nicola.farina_at_info-line.it> wrote in message news:1133458801.702373.151130_at_g43g2000cwa.googlegroups.com...
>I could try but these are dynamically generated views.
> I tried setting the parameter
> alter session set "_optimizer_sortmerge_join_enabled"=false;
> and the cartesian merge goes away
> BUT
> what are the drawbacks of this "solution" ?
>

The drawback to that solution is that you may find some cases where you can't
do a sort/merge join when it's the only
efficient thing to do.

I'm having trouble working out why
that parameter exists. The best answer
I can come up with is that it's there so the developers can test some code paths
without putting in 'no_use_merge()' hints in their test scripts.

-- 
Regards

Jonathan Lewis

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