Trying to make use of bitmap indexes
631129May 24 2008 — edited May 30 2008Hello!
I have a table that contains about 16 mill rows and each night about
60.000-70.000 rows are proccessed against the table so that part of the rows
is updated and another part is inserted.
The table contains three IDEAL columns for bitmap indexes the first of which
may have only two, the second three and the third four distinct values.
I was planning to change the index type on these columns to BITMAP but
Oracle doesnt recommend to build BITMAP indexes on heavily updated or inserted
columns.
So the only use of bitmap indexes turns out to be read-only tables.
From the other hand a sloution might be dropping indexes before the load and rebuilding them after the load has completed what can lead to often tablespace fragmentations.
So, the question is how can I use bitmap indexes in a case like this one?
What are wayouts?
Thank you very mcuh for the reply.