I am using Oracle 9i Database.

I have built a sales schema for my data mart, which include 7
dimension tables and one fact table.

I DONT have any olap engine.

Can anyone guide me or give me some hints how I can provide the
olap functionality by using only oracle 9i database.
Some one told be about materialized views and query rewrite features
of oracle 9i, but how can I
precalculate all aggregations. If i precalculate only few aggregation then
how can i decide that which few aggrigations are to be precalculated
and which should be calculated at runtime.

Thanks in Advance