Question

I am optimizing sql query and I am welcoming advices how to improve this query. It’s part of nopcommerce open source solution for loading products in categories. At this time it takes some 8-9 seconds to load the page, we want to bring that to 3-4 seconds if we can.

Here is the query, I am welcoming every advice how I can improve that:

ALTER PROCEDURE [dbo].[Nop_ProductLoadForCategory]
(
    @CategoryID         int = 0,
    @manufacturerId     int = 0,
    @PageIndex          int = 0, 
    @PageSize           int = 2147483644,   
    @TotalRecords       int = null OUTPUT,
    @VehiclesYear       varchar(4) = null,
    @VehiclesMake       varchar(20) = null,
    @VehiclesModel      varchar(50) =null,
    @VehiclesSubmodel       varchar(50) =null,
    @Universal bit = 1
)
AS
SET NOCOUNT ON
BEGIN

    --paging
    DECLARE @PageLowerBound int
    DECLARE @PageUpperBound int
    DECLARE @RowsToReturn int

    SET @RowsToReturn = @PageSize * (@PageIndex + 1)    
    SET @PageLowerBound = @PageSize * @PageIndex
    SET @PageUpperBound = @PageLowerBound + @PageSize + 1

    CREATE TABLE #DisplayOrderTmp 
    (
        [ID] int IDENTITY (1, 1) NOT NULL,
        [ProductID] int NOT NULL
    )


    if isnull(@manufacturerId, 0) = 0
        if @Universal = 1
            INSERT INTO #DisplayOrderTmp ([ProductID])
            select a.ProductID from (
                SELECT TOP 100 PERCENT 
                    row_number() over(order by pv.DisplayOrder) as ID,
                    p.ProductID
                FROM dbo.Nop_Product p with (NOLOCK) 
                INNER JOIN Nop_Product_Category_Mapping pcm with (NOLOCK) ON p.ProductID=pcm.ProductID
                LEFT OUTER JOIN Nop_ProductVariant pv with (NOLOCK) ON pv.ProductID = p.ProductId
                left outer join WC_ProductVehicleApplications pva with (NOLOCK) on pva.ProductID=p.ProductId
                left outer join [WC_Vehicles] v with (NOLOCK) on pva.VehicleID = v.VehicleID
                WHERE 
                   (pcm.CategoryID=@CategoryID)
                    AND (p.Published = 1)
                    AND (p.Deleted=0)       
                    and (((@VehiclesYear between [YEAR] and YearEnd or @VehiclesYear is null)
                    and ([Make] = @VehiclesMake or @VehiclesMake is null)
                    and ([Model] = @VehiclesModel or @VehiclesModel is null)            
                    and ([SubModel] = @VehiclesSubmodel or @VehiclesSubmodel is null))
                    or p.IsUniversal = 1)
                ) a 
                GROUP BY 
                ProductID
            ORDER BY 
                min([ID])

        else
            INSERT INTO #DisplayOrderTmp ([ProductID])
            select a.ProductID from (
                SELECT TOP 100 PERCENT 
                    row_number() over(order by pv.DisplayOrder) as ID,
                    p.ProductID
                FROM dbo.Nop_Product p with (NOLOCK) 
                INNER JOIN Nop_Product_Category_Mapping pcm with (NOLOCK) ON p.ProductID=pcm.ProductID
                LEFT OUTER JOIN Nop_ProductVariant pv with (NOLOCK) ON pv.ProductID = p.ProductId
                left outer join WC_ProductVehicleApplications pva with (NOLOCK) on pva.ProductID=p.ProductId
                left outer join [WC_Vehicles] v with (NOLOCK) on pva.VehicleID = v.VehicleID
                WHERE 
                   (pcm.CategoryID=@CategoryID)
                    AND (p.Published = 1)
                    AND (p.Deleted=0)       
                    and (((@VehiclesYear between [YEAR] and YearEnd or @VehiclesYear is null)
                    and ([Make] = @VehiclesMake or @VehiclesMake is null)
                    and ([Model] = @VehiclesModel or @VehiclesModel is null)            
                    and ([SubModel] = @VehiclesSubmodel or @VehiclesSubmodel is null))
                    and p.IsUniversal <> 1)
                ) a 
                GROUP BY 
                ProductID
            ORDER BY 
                min([ID])
    else            
            INSERT INTO #DisplayOrderTmp ([ProductID])
            select a.ProductID from (
                SELECT TOP 100 PERCENT 
                    row_number() over(order by pv.DisplayOrder) as ID,
                    p.ProductID
                FROM dbo.Nop_Product p with (NOLOCK) 
                INNER JOIN Nop_Product_Category_Mapping pcm with (NOLOCK) ON p.ProductID=pcm.ProductID
                LEFT OUTER JOIN Nop_ProductVariant pv with (NOLOCK) ON pv.ProductID = p.ProductId
                left outer join WC_ProductVehicleApplications pva with (NOLOCK) on pva.ProductID=p.ProductId
                left outer join [WC_Vehicles] v with (NOLOCK) on pva.VehicleID = v.VehicleID
                WHERE 
                   (pcm.CategoryID=@CategoryID)
                    AND (p.Published = 1)
                    AND (p.Deleted=0)       
                    and (((@VehiclesYear between [YEAR] and YearEnd or @VehiclesYear is null)
                    and ([Make] = @VehiclesMake or @VehiclesMake is null)
                    and ([Model] = @VehiclesModel or @VehiclesModel is null)            
                    and ([SubModel] = @VehiclesSubmodel or @VehiclesSubmodel is null))
                    or p.IsUniversal = 1)
                ) a 
                GROUP BY 
                ProductID
            ORDER BY 
                min([ID])


    --CREATE UNIQUE NONCLUSTERED INDEX IX_1 on #DisplayOrderTmp ([ID], [ProductID])

    --CREATE TABLE #PageIndex 
    --(
    --  [IndexID] int IDENTITY (1, 1) NOT NULL,
    --  [ProductID] int NOT NULL
    --)

    --INSERT INTO #PageIndex ([ProductID])


    --SELECT TOP 100 PERCENT 
    --  Row_Number() Over(Order By min([ID])) as RowNum, ProductID
    --FROM #DisplayOrderTmp with (NOLOCK)
    --GROUP BY ProductID
    --ORDER BY min([ID])

    --select ProductID
    --FROM #DisplayOrderTmp with (NOLOCK)
    --GROUP BY ProductID

    --SELECT 
    --  ProductID
    --FROM 
    --  #DisplayOrderTmp with (NOLOCK)
    --GROUP BY 
    --  ProductID
    --ORDER BY 
    --  min([ID])

    --select ProductID from #DisplayOrderTmp with (NOLOCK) --order by min([ID])


    --CREATE UNIQUE NONCLUSTERED INDEX IX_2 on #PageIndex ([IndexID], [ProductID])

    --total records
    SET @TotalRecords = @@rowcount  
    SET ROWCOUNT @RowsToReturn



    --DROP TABLE #DisplayOrderTmp

    --return

    SELECT 
        p.ProductId,
        p.Name,
        p.ShortDescription,
        p.FullDescription,
        p.AdminComment,
        p.TemplateId,
        p.ShowOnHomePage,
        p.MetaKeywords,
        p.MetaDescription,
        p.MetaTitle,
        p.SEName,
        p.AllowCustomerReviews,
        p.AllowCustomerRatings,
        p.RatingSum,
        p.TotalRatingVotes,
        p.Published,
        p.Deleted,
        p.CreatedOn,
        p.UpdatedOn,
        p.[IsUniversal],
        p.FullDescriptionSave
    FROM
        --(SELECT TOP 100 PERCENT 
        --  Row_Number() Over(Order By min([ID])) as RowNum, ProductID
        --FROM #DisplayOrderTmp with (NOLOCK)
        --GROUP BY ProductID
        --ORDER BY min([ID])
        --) [pi]
        --inner join 
        #DisplayOrderTmp [pi] 
        --on dot.ProductID = [pi].ProductID
        INNER JOIN Nop_Product p with (NOLOCK) on p.ProductID = [pi].ProductID 
        INNER JOIN Nop_Product_Category_Mapping pcm with (NOLOCK) ON p.ProductID=pcm.ProductID
    WHERE
        --[pi].IndexID > @PageLowerBound AND 
        --[pi].IndexID < @PageUpperBound
        [pi].ID > @PageLowerBound AND 
        [pi].ID < @PageUpperBound
    ORDER BY
        [pi].ID 

    SET ROWCOUNT 0


    DROP TABLE #DisplayOrderTmp
END

Thanks in advance, Laziale

Answer 1

OK, so you have 45,000 reads and 2000 CPU. These numbers are generally high, and the query can likely be optimized. The Profiler screen shot is clipped. How many rows are returned?

Can you edit your question & post the execution plan?

Notice, however, that SQL only thinks the query took 651 milliseconds. If you’re seeing 8-9 second delay, the issue is likely in the client code. That is the first place I would spend time optimizing (unless your query returns gobs of rows that are discarded in the client).