SQL Query too slow on SUM function I've a table with around 32 million rows having clustered unique index on CountryID,RetailerID,ProductID,DateID,EventID,TypeID and query is

SELECT  f.RetailerID
,       TypeID                                AS TypeID
,       c.CalendarMonth                         AS CalendarValue                    
,       SUM(ISNULL([Volume],0)                  ) AS Volume
,       SUM([VolumeBox]                         ) AS VolumeBox
,       SUM([VolumeKG]                          ) AS VolumeKG
,       SUM([VolumeUnit]                        ) AS VolumeUnit
,       SUM(ISNULL([R_Turnover] , 0.0)          ) AS R_Turnover
,       SUM(ISNULL([R_VAT],0.0)                 ) AS R_VAT
,       SUM(ISNULL([R_TurnoverExVAT],0.0)       ) AS R_TurnoverExVAT
,       SUM([SupplierRealisation_Amt]           ) AS [SupplierRealisation_Amt]
,       SUM([SupplierDiscount1_Amt]             ) AS [SupplierDiscount1_Amt]
,       SUM([Supplier_1NetSales_Amt]            ) AS [Supplier_1NetSales_Amt]
,       SUM([SupplierDiscount2_Amt]             ) AS [SupplierDiscount2_Amt]
,       SUM([Supplier_2NetSales_Amt]            ) AS [Supplier_2NetSales_Amt]
,       SUM([SupplierDiscount3_Amt]             ) AS [SupplierDiscount3_Amt]
,       SUM([Supplier_3NetSales_Amt]            ) AS [Supplier_3NetSales_Amt]
,       SUM(ISNULL(S_CostofGoodsSold, 0)        ) AS [S_CostofGoodsSold]
,       SUM(ISNULL(S_Profit, 0)                 ) AS S_Profit
,       SUM(0.0                                 ) AS AdditionalCostofGoodsSold
,       SUM(ISNULL([R_DistributionCost],0.0)    ) AS R_DistributionCost
,       SUM(ISNULL([R_Profit],0.0)              ) AS R_Profit
FROM [dbo].[EventScenarios] es 
JOIN dbo.[Event] e ON es.[EventID] = e.ID  
JOIN dbo.EventProduct ep on es.EventID = ep.EventID 
JOIN [dbo].Product p ON p.ID=ep.ProductID 
JOIN dbo.EventPL f  ON  e.CountryID = f.CountryID AND f.RetailerID = e.RetailerID AND f.EventID = e.ID
AND ep.ProductID = f.ProductID  
INNER JOIN Calendar c   ON  c.DateID = f.DateID   
WHERE  f.CountryID= 14  AND c.CalendarMonth BETWEEN 201301  AND 201312 
GROUP BY f.RetailerID , c.CalendarMonth ,TypeID  


The query plan is showing 88% time on Clustered Index seek on EventPL table but still its taking around 15 seconds to complete. Is there any way I can optimise it to around 1/2 seconds?



Query Plan XML Link
(Moved my comment to an answer, and expanded a bit.)


  I cannot create indexed views as I've some calculations as well like SUM(Volume * CaseCount) AS SomeColumn which is not allowed in indexed views and also it's a dynamic query and grouping and joins are based on user input.


From the plan you provided, the clustered index scan is 3.5x overestimated, and the Sort is an order of magnitude underestimated which caused a spill to tempdb. Performance may improve after updating statistics.

However, based on your reply, if this schema is servicing "random" queries against that amount of data, it's going to be extremely challenging and/or expensive to get good performance for all the possible combinations.

For this type of workload, I think the only realistic way to meet the performance goal would be to abandon trying to find a database engine solution, and use Analysis Services instead.