query not using bitmap index

I have a table like
entry(id, type)

The type column is very nondistinct. I created a bitmap index entry_type_Bmp on it.
A query like
select /*+ index (entry entry_type_Bmp ) */ * from entry where type ='atype' does not use the index and is slow. It get unbearable when I join this table whith type specification in the where-clause and a full scan is performed.

The index entry_type_Bmp is indeed active since this query select count('x') from entry where type ='atype' uses it, as seen from the plan.

Wth a type given in the where-clause, it is apparent that use of the index should avoid a full table scan. The hint didn't have effect. what are my options?

Kenny Received on Wed Oct 16 2002 - 19:18:39 CDT