Workflow- ABAP performance question

Question

hi ,
we were doing to couple of test.
i have include a select statement
Below logic takes 700,000 micro seconds to run in a dev environment
TYPES: Begin of ty_test,
        meth_edate LIKE sy-datum,
       End of ty_test.
DATA:  it_workitem TYPE STANDARD TABLE OF ty_test
                           WITH NON-UNIQUE KEY meth_edate
                           INITIAL SIZE 100.
SELECT meth_edate FROM sww_outbox
   I                              NTO TABLE it_workitem
                                  WHERE meth_edate EQ sy-datum.
Where as
Below logic only takes 2000 micro seconds
DATA : it_workitems LIKE SWWWLHEAD occurs 0
                                   WITH HEADER LINE.
SELECT * FROM sww_outbox
   INTO CORRESPONDING FIELDS OF TABLE it_workitems
                WHERE meth_edate EQ sy-datum.
I couldnt believe how come logic which I thought takes more time is taking less time. Any particular reason for such big difference. I am guessing I am missing something.
But I need to optimize code from 2000 micro second to lesser ..any suggestion

Answer 1

SELECT * FROM sww_outbox
INTO CORRESPONDING FIELDS OF TABLE it_workitems
WHERE meth_edate EQ sy-datum.
You can  increase performance by removing the INTO CORRESPONDING FIELDS OF TABLE.... this is the addition of select statement which would be taking time to get the data from SWW_OUTBOX table....
Instead of * you can write selective fields which ever you are trying to read into the table... this modification could improve the select statement performance..