Help on Sqexplain output.

Hi all, Recently we upgraded our system from 5.0 to 7.23 DSA which is running on a DYNIX Sequent box. We are facing a performance problem in one of our program. which used to take about 5 hours now it is taking 30 hours to process. I have gone through the sqexplain.out and did all the update statistics for the table etc. The only thing I found the cost which was very high is the following QUERY: ------ insert into iv_dly_rec_energy ( mtr_pnt_ref, inv_no, mtr_period_day,var_dly_rec _energy) values (?,?,?,?) Estimated Cost: 64606 Estimated # of Rows Returned: 1774359 where the table has about iv_dly_rec_energy has about 1.7 million rows. Is the cost which is shown above is alright or it too high? does the cost for an insert make any sense in the sqexplain output?. Any suggesstions?. Thanks in advance. Jay