Oracle Database Discussions

Hi,
we are using oracle 10g (10.0.2.0.3 version). We have table1 which had 4 million records lastweek.
For better performance, we decided to move records less than JULY 2010 to history table (table2) which is created as like table1. We used INSERT INTO TABLE2 SELECT * FROM TABLE1 WHERE STARTDATE < TO_DATE('070110','MMDDYY') query. It has moved some 3.5 million records from table1 to table2.

After moving these records, we have deleted the moved records from table1. Our query is accessing only table1.

We have expected better performance. But after this Move and Delete operation, Oracle performance is very slow. It is taking more than 30 to 50 sec to insert single record into table1 which is currently having only 400000 records alone.

We have index on STARTDATE field in table1. We have recreated the index and rebuild it and we restarted the server also. But it dont make any difference. Oracle performance is very slow.

How to solve this problem?

Regards,
Senthil