Re: RULE vs COST based optimiser

>grant_at_towersoft.com.au (Fuzzy) wrote:
>>Any ideas on this problem would be much appreciated.
 

>>A 750 Meg Oracle database is split roughly between 500 Meg of data and
>>250 Meg of indexes. However, the db is set to rule-based optimising.
>>I think it should be set to cost-based (otherwise serious resources
>>are being wasted on maintaining indexes, statistics, etc), but the
>>customer is dubious. Any ideas on what kind of improvement (if any)
>>will be made by switching to cost-based?

Please explain me how using cost-basted optimization is going to improve resource usage. Cost-based means calculating statistics, and the indexes you'll need whether you use cost or rule based.

Andrej

-- 
------------------------------------------------------------------------------
Andrej Koelewijn                                     Phone:     +31-30-6931310 
REDWOOD Nederland B.V.                               Fax:       +31-30-6930477
Princenhof Park 13                                   E-mail: andrej_at_redwood.nl  
3972 NG  DRIEBERGEN                    
The Netherlands                       
------------------------------------------------------------------------------