Re: Cost of Access Plan using Bitmap Indexes

Jonathan thanks a lot.

Your advices are great food for thought and help me understand the picture behind.

Still one question remain:
in the Oracle Datawarehousing guide there is a lot of enphasis on Bitmap indexes and the way they can be merged easily by the optimizer helping getting the best from the very different report (SQL) that can be generated in a DSS environment,but at the moment I have seen that CBO consider even a full table scan way cheaper then the bitmap indexes.

Considering that fact tables are pretty big is my only option to be killed by millions of phisycal reads or to go for hints?
that by the way not always can be implemented?

thank you very much again and hope to see other good advices on the topic.

P.s. using a bigger Bitmap_sorting _area could help cutting the cost?

Best Regards,
Fabrizio  

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