Question

I’ve got a query that’s been driving me up the wall. The t-sql query is as follows but with about a thousand records in the source table, it’s taking forever and a day to run. Is there any faster way of accomplishing the same task anyone might think of:

SELECT *, ROUND((SELECT SUM(PartTotal) 
FROM PartSalesRankings 
WHERE Item_Rank <= sub.Item_Rank) /
 (SELECT SUM(PartTotal) 
  FROM PartSalesRankings) * 100, 2) as Cum_PC_Of_Total 
FROM PartSalesRankings As sub

I’m trying to classify my inventory into A,B, and C categories based on percentage of cost, but it needs to be a cumulative percentage of cost, ie. ‘A’ parts make up 80% of my cost, ‘B’ parts make up the next 15%, and ‘C’ parts are the last 5%. There’s obviously more to the sql statement than what I included, but the code I posted is the bottle-neck.

Any help would be greatly appreciated!

Aj

Answer 1

Sorry for the delay in response, but I’ve been up to my neck in other stuff, but after a great deal of trial and error I’ve found the following to be the fastest method:

Select companypartnumber
     , (PartTotal + IsNull(Cum_Lower_Ranks, 0) ) / Sum(PartTotal) over() * 100 as Cum_PC_Of_Total
    from PartSalesRankings PSRMain
   Left join 
        (
            Select PSRTop.Item_Rank, Sum(PSRBelow.PartTotal) as Cum_Lower_Ranks
              from partSalesRankings PSRTop
              Left join PartSalesRankings PSRBelow on PSRBelow.Item_Rank < PSRTop.Item_Rank
             Group by PSRTop.Item_Rank 
        ) as PSRLowerCums on PSRLowerCums.Item_Rank = PSRMain.Item_Rank
) sub2