Hi Thanga,
If you are not using update task ( CALL FUNCTION IN UPDATE TASK ) / background tasks(CALL FUNCTION IN BACKGROUND TASK ), then commit work statement is optional. System will do implicit commit after the program ends. However to be on the safer side, you should explicitly code it.
https://help.sap.com/abapdocu_70/en/ABAPCOMMIT.htm
Please note that - If you are directly updating the table in your program without using update task, no entry exists in SM13- Monitor Update task.
Regards,
DPM