Hi All, Our web application uses SQL Server 2005 and above versions. Currently we are facing performance issues under load. We have a table with 4milliion records. The table has more than 100 columns. The end user can apply filter on any of those 100 columns. Hence we created non-clustered indexs for all the columns (Each column has 1 non-clustered index). And a clustered index (Primary Column) for ID column whihch will have alpha-numeric data. The query that will be generated at run-time will be as below: BEGIN With TEST as ( select ROW_NUMBER() over( order by x, y asc) as RN, ROUND(AVG(a),5), ROUND(AVG(b),5)........ FROM Table1 Where z >= 3260 Group by x , y) select * from TEST where RN BETWEEN 1 AND 200 order by RN; END I cehcked the execution plan and found that Clustered index scan has 99% whihch uses only Primary key for search. Meaning the non-clustered index created on the column is not being utilized. When did a load test, out of 10 users, 3 got blank page and the rest of them had a result in less than 20secs. Can somebody let me know what changes can be done so that the above query gets executed successfully under load. Note: There could be more than 4m records in that table. The target is 34m. But this is failing even for 4m.