CHOOSE is the same as ALL_ROWS assuming you have
statistics loaded on all of your tables. CHOOSE
simply means
- if there are NOT stats, use RULE
- if there ARE stats, use ALL_ROWS
hth
connor
- Cherie_Machler_at_gelco.com wrote: >
> Someone in our development group is recommending
> that OPTIMIZER_MODE be set
> to ALL_ROWS in our 9i databases. Everything that
> I've read recommends
> setting OPTIMIZER_MODE to choose.
>
> These are a medium-size ODS database that will have
> reads and writes and a
> smallish data warehouse and datamart that are going
> to be used mostly for
> reporting purposes.
>
> Why wouldn't I want to let Oracle choose? I think
> the optimizer is
> working better than ever in 9.2. Why would I want
> to set up the whole
> database as ALL_ROWS? Normally, I just use that as
> a hint in batch jobs
> or reports. Am I off-base?
>
> Thanks,
>
> Cherie Machler
> Oracle DBA
> Gelco Information Network
>
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> Author:
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Received on Mon Aug 05 2002 - 11:13:20 CDT