You mean you have a table with columns mth_01, mth_02, ... mth_12? Looks like a perfect example of an incorrectly designed table to me. Let's suppose the pac.historyreportmonthlybysku had columns id,loc,dmdunit (primary key is the id) and there was a table pac.historyreportmonthlybyskuval with columns id,mth,qty (where mth is the number of month and qty is the value for that month, primary key is (id,mth)):

SELECT GREATEST(
     ROUND(SELECT SUM(qty) FROM pac.historyreportmonthlybyskuval as hv
+ WHERE hv.id = h.id),
     ROUND(SELECT SUM(qty) FROM pac.historyreportmonthlybyskuval as hv
+ WHERE hv.id = h.id and mth >= ? and mth <= 11)
    ) QTY,
    b.p_dlrnet, b.p_dlrsplrcode   
  FROM pac.historyreportmonthlybysku h -- at least use meaningfull let
+ters!
  JOIN stsc.sku ON sku.loc = h.loc and sku.ITEM = h.dmdunit
 WHERE a.loc     = ?
   AND a.dmdunit = ?
 GROUP BY a.loc, a.dmdunit, b.p_dlrnet, b.p_dlrsplrcode
[download]

No need for dynamic SQL. So you are more likely to be able to reuse the query plan instead of forcing Oracle to recompile and reoptimize your query every time.

{REM}I think I'll go crazy when I finally move to (name snipped to protect the quilty) with their 8500 tables in the database. A separate table for the usernames&passwords of each client ... oh my! And the butt that deserves to be kicked is long gone.{/REM}