Function-based indexes

I can see that FBI (!) would be useful in the classic case of case insensitive string matching

where upper(column)=upper('input string')

To serve the above query, one would
create index on table (upper(column))

But if I know the case in which a particular data element is stored and were to use a
 where column='This Way'

would it still use the FBI?

Of course, I am assuming that you cannot have a FBI and any other index (btree or bitmap) on the same column?

In general, how exactly does the FBI work internally? The docs mention that it stores the data using a 'expression tree' and not a 'btree'. What does this mean exactly? Does Oracle evaluate the function and actually store the upper-cased values in the index?

If it is not a btree, arent there any leaf nodes? How is the index organized then?

Thanks... Received on Wed Apr 04 2001 - 08:31:47 CDT