Re: Bitmap index costing - how to influence
- From: Riyaj Shamsudeen <riyaj.shamsudeen@xxxxxxxxx>
- To: info@xxxxxxxxxxxxxxxxxxxxx, kutrovsky.oracle@xxxxxxxxx
- Date: Sun, 29 Mar 2009 10:10:39 -0500
Hi Christo
May be, you are only interested in finding a generic solution for all
bitmap indices in that atabase. But, How many columns are in that bitmap
index chosen? Do you get any relief if you create single column bitmap
index?
--
Cheers
Riyaj Shamsudeen
Principal DBA,
Ora!nternals - http://www.orainternals.com
Specialists in Performance, Recovery and EBS11i
Blog: http://orainternals.wordpress.com
On Sun, Mar 29, 2009 at 7:02 AM, Randolf Geist
<info@xxxxxxxxxxxxxxxxxxxxx>wrote:
> > Why use undocumented OPT_PARAM when INDEX_COMBINE is documented and
> > provided?
>
> Greg,
>
> thanks for making that point. I generally second that one shouldn't use
> undocumented parameters/features if possible. Unfortunately Oracle doesn't
> provide (yet) an officially documented way to influence parameters like OICA
> / OIC on statement level, that's why I suggested it in this particular case
> to limit the effects of this parameter as much as possible.
>
> There are obviously many different possibilities how the index usage in
> this particular case could be hinted/forced, but the INDEX_COMBINE and the
> OPTIMIZER_INDEX_COST_ADJ suggestions provide quite different means, so it
> depends what the objective is in the particular situation.
>
> Regards,
> Randolf
>
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