Re: Number 1 gripe about CBO: 0 <Cardinality< 1 (?????)

On Apr 4, 5:16 pm, "Kevin Kirkpatrick" <kvnkrkpt..._at_gmail.com> wrote:

>
> > - have no join clause between kk_small and kk_big, yet you list them
> > in this order, which is obeyed by CBO.
>
> Did I just step into the twighlight zone? Syband, this comment makes
> so little sense that I'm literally stumped as to how to reply. Do you
> know even know what the CBO is?
>
> > What else do you expect?
>
> Certainly not a response from a "Senior Oracle DBA" who thinks that
> the CBO chooses join order based on the order in which tables are
> listed in a query...

In the case of tie-breakers, that is, where the optimizer thinks the cost is equal for two join orders, RBO worked from last to first, CBO works in order written, IIRC.

jg

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