Performance of a query

Hi,

The below query is being used by a cursor in a stored procedure of a concurrent program.So the concurrent program is taking really long time to complete. 

I am trying to find out ways to improve the performance of this query. Please help !!!

Query:

The table ccpe has

5943462 number of rows

(SELECT  ccpe.location,

                      ccpe.client,

                      ccpe.due_date,

                      ccpe.prod,

                      ccpe.p_number,

                      ccpe.comm_type,

                      ccpe.product,

                      ccpe.loc,

                      ccpe.net_due,

                      (CASE

                          WHEN (TO_DATE (period, 'MON-YYYY') >= :v_cy_date_from

                                                                 AND TO_DATE (period, 'MON-YYYY') <= :v_cy_date_to)

                          THEN

                             1

                          ELSE

                             0

                       END)

                         AS cy_factor,