aa8d7cd2_Cost_Based_Oracle_Fundamentals__Comments
[Chapter] Chapter 8 [Last addendum] 30th Dec 2005 [Title] Bitmap Indexes [Comments] 
There are a couple of critical differences between B-tree indexes and Bitmap indexes. It’s easy to overlook these differences – but the most significant one is that the clustering_factor for bitmap indexes does not mean the same thing as it does for B-trees – so something has to replace it. Oracle then has a special strategy for combining bitmap indexes that needs its own costing model.
Cost Based Oracle Fundamentals
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