Commented by: Sean Leyne (seanleyne)

Please explain further.

Firebird currently creates all indexes as bitmaps, so I don't understand what change you are looking for.

Commented by: @asfernandes

Never used it, but accordingly to Oracle documentation, its bitmap index seems crap. It's read-only and probably just for OLAP usage.

Commented by: @dyemanov

Well, Firebird does not create indices as bitmaps. Neither they're read-only in Oracle.

But I agree this feature is of somewhat limited use. It makes sense only for columns with extremely low selectivities which data is modified rarely (because of high maintaining cost for a bitmap index).

Commented by: Thiago Borges (thborges)

And what about bitmap join index?
I have recently solved performance issues in Oracle with this type of index.
The relations in my case are PARTS and ITEMS. I need to query them filtering a interval on PARTS.DATE and a specific ITEMS.PRODUCT. Each field is in one of the tables.