SQL> SELECT * FROM TEST_DW;

      DWID STARTTIME   ENDTIME         AMOUNT
---------- ----------- ----------- ----------
         1 1/1/2008    1/4/2008             5
         1 1/3/2008    1/6/2008             5
         2 1/1/2008    1/4/2008             5
         2 1/3/2008    1/6/2008             5
         1 1/7/2008    1/12/2008            6
         2 1/7/2008    1/11/2008            8
         1 1/13/2008   1/16/2008           10

7 rows selected

SQL> SELECT DWID,
  2         AMOUNT,
  3         DWID+AMOUNT "NEW_DWID"
  4    FROM TEST_DW;

      DWID     AMOUNT   NEW_DWID
---------- ---------- ----------
         1          5          6
         1          5          6
         2          5          7
         2          5          7
         1          6          7
         2          8         10
         1         10         11

7 rows selected