Re: CBO - hash join vs nested loops

> - Should those queries be written such that CBO is forced to take what the
> developer thinks is an optimal plan? Interestingly, here the old good
> NL-loop turns out to be a better plan than hashing, scanning, etc.

> - Is the first thing to do with the Oracle instance that to tune OCI?
> Should high OIC values (the "correct 99.9) be tested immediately? (This is
> actually what I do - set all OLTP or general purpose instances to favour
> indexes.)

I think the correct approach is to tune immediately the OIC, but for that I have to verify the behaviour of all the problematic statements with the new settings.
I repeat, I have an issue that looks very similar on more than one 9ir2 instance.

Regards,
Dimitre Radoulov

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