0 - 2 of 2 tags for Query optimizations

Hi All,
We are inserting data in an empty table through 2 Insert...Select statements in our Bteq scripts One of which is Consuming a lot of CPU Time (2 hours )though it is inserting 3.6 Million rows.
We reached our DBA's for any possibility of Query Optimization.

Hi Experts,
I am bit unclear about the OCES-3 (Optimizer Cost Estimation Subsystem version 3) in the stats area  and BMSMS (bit map set manipulation set) in the Query execution.
Can any one please suggest some pointers for the above topics to deep dive in it..