Question

This view query is taking 2min to load 500 000 lines.
I’m using EF 4.0 and thread load this view on a DataGrid.
How can I optimize it so it can load in shorter time ?

Update : I updated the query to this and now it takes 55 seconds but still too long !

SELECT  ROW_NUMBER() OVER ( ORDER BY ss.IDStore_CardStore DESC ) AS Id_PK ,
        SC.IDStockCardIndex ,
        SC.Designation ,
        ISNULL(P.PMP, 0) PMP ,
        ISNULL(SS.Quantity, 0) Quantity ,
        SS.UnitePrice * SS.Quantity AS SubTotalStockCard ,
        S.StoreName ,
        SS.IDPurchaseInvoice
FROM    dbo.Stores S
        INNER JOIN dbo.StockCardsStores ss ON S.IDStore = ss.IDStore
        RIGHT OUTER JOIN dbo.StockCard SC ON ss.IDStockCardIndex = SC.IDStockCardIndex
        LEFT OUTER JOIN ( SELECT    SUM(UnitePrice * Quantity) / SUM(Quantity) AS PMP ,
                                    IDStockCardIndex
                          FROM      dbo.StockCardsStores AS SCS
                          GROUP BY  IDStockCardIndex
                        ) AS P ON P.IDStockCardIndex = SC.IDStockCardIndex

Answer 1

Use Estimate Execution Plan in SSMS. If you’re using 2008 R2, SSMS will suggest “missing index” that will possibly improve the time overall. 500,000 rows at 55 seconds suggest that one or more table scans are kicking in. The Estimated Execution Plan will identify these. The Plan will also show what part of the query “costs” the most overall, helping you to zero in.

Highlight that inner sub-query and look at the plan for that first. Then work your way outwards.