SQL遞歸層次結構非常慢

Question

因此，我剛完成一項優化SQL查詢的任務，該SQL查詢構建了產品，內部產品，制造操作，操作細節和項目（制造產品所需）的層次結構樹。 該查詢返回218k行，可以正常工作，但是大約需要15-18秒來構建樹。 是否可以優化該查詢，因此大約需要2-3秒？ 如果我將@ProductID添加為該過程的參數並執行

WHERE ProductID = @ProductID

從“產品”表中選擇后，它的運行速度非常快，但是樹卻不完整，因為如果我為其構建樹的產品是內部產品，則其父產品不會顯示在樹中。 將所有這些表加載到C＃應用程序並在那里進行所有層次結構構建會更快嗎？

我願意接受所有想法。 下面是有問題的查詢

  ALTER PROCEDURE [dbo].[ProductProduct_selectHierarchy_v2]
WITH EXECUTE AS CALLER
AS
BEGIN
WITH ProductProductHierarchy (
    ProductID
    ,ItemProductID
    ,LEVEL
    ,UniqueID
    ,ParentID
    ,RowType
    ,ProductDetailID
    ,ProductProductDetailBindID
    ,ManufactoryOperationID
    ,ItemID
    )
AS (
    -- Anchor member definition
    SELECT dbo.Product.ProductID AS ProductID
        ,Product.ProductID AS ItemProductID
        ,0 AS LEVEL
        ,Cast(cast(Product.ProductID AS NVARCHAR(40)) + '' AS NVARCHAR(50)) AS UniqueID
        ,cast('' AS NVARCHAR(50)) AS ParentID
        ,1 AS RowType
        ,NULL AS ProductDetailID
        ,NULL AS ProductProductDetailBindID
        ,NULL AS ManufactoryOperationID
        ,NULL AS ItemID
    FROM dbo.Product

    UNION ALL

    -- Recursive member definition
    SELECT e.ProductID
        ,e.ItemProductID
        ,LEVEL + 1
        ,Cast(Cast(d.UniqueID AS NVARCHAR(40)) + '_' + cast((e.ItemProductID) AS NVARCHAR(10)) AS NVARCHAR(50)) AS UniqueID
        ,Cast(d.UniqueID AS NVARCHAR(50)) AS ParentID
        ,1 AS RowType
        ,NULL AS ProductDetailID
        ,NULL AS ProductProductDetailBindID
        ,NULL AS ManufactoryOperationID
        ,NULL AS ItemID
    FROM dbo.ProductProduct AS e
    INNER JOIN ProductProductHierarchy AS d ON e.ProductID = d.ItemProductID

    UNION ALL

    SELECT NULL AS ProductID
        ,NULL
        ,LEVEL + 1
        ,Cast(Cast(d.UniqueID AS NVARCHAR(40)) + '_' + cast((e.ProductDetailID) AS NVARCHAR(10)) AS NVARCHAR(50)) AS UniqueID
        ,Cast(d.UniqueID AS NVARCHAR(50)) AS ParentID
        ,2 AS RowType
        ,e.ProductDetailID AS ProductDetailID
        ,e.ProductProductDetailBindID AS ProductProductDetailBindID
        ,NULL AS ManufactoryOperationID
        ,NULL AS ItemID
    FROM dbo.ProductProductDetailBind AS e
    INNER JOIN ProductProductHierarchy AS d ON e.ProductID = d.ItemProductID

    UNION ALL

    SELECT NULL AS ProductID
        ,NULL
        ,LEVEL + 1
        ,Cast(Cast(d.UniqueID AS NVARCHAR(40)) + '_' + cast((e.ManufactoryOperationID) AS NVARCHAR(10)) AS NVARCHAR(50)) AS UniqueID
        ,Cast(d.UniqueID AS NVARCHAR(50)) AS ParentID
        ,3 AS RowType
        ,NULL AS ProductDetailID
        ,NULL AS ProductProductDetailBindID
        ,e.ManufactoryOperationID AS ManufactoryOperationID
        ,NULL AS ItemID
    FROM dbo.ProductDetailOperation AS e
    INNER JOIN ProductProductHierarchy AS d ON e.ProductProductDetailBindID = d.ProductProductDetailBindID

    UNION ALL

    SELECT NULL AS ProductID
        ,NULL
        ,LEVEL + 1
        ,Cast(Cast(d.UniqueID AS NVARCHAR(40)) + '_' + cast((e.ItemID) AS NVARCHAR(10)) AS NVARCHAR(50)) AS UniqueID
        ,Cast(d.UniqueID AS NVARCHAR(50)) AS ParentID
        ,4 AS RowType
        ,NULL AS ProductDetailID
        ,NULL AS ProductProductDetailBindID
        ,NULL AS ManufactoryOperationID
        ,e.ItemID AS ItemID
    FROM dbo.ProductItem AS e
    INNER JOIN ProductProductHierarchy AS d ON e.ProductID = d.ItemProductID
    )
-- Statement that executes the CTE
SELECT CASE 
        WHEN RowType = 1
            THEN ProductName + '<' + ProductCode + '>'
        WHEN RowType = 2
            THEN ProductDetail.ProductDetailName
        WHEN RowType = 3
            THEN ManufactoryOperation.ManufactoryOperationName
        ELSE Item.ItemName
        END AS ProductName
    ,UniqueID
    ,ProductProductHierarchy.ParentID
    ,Product.ProductID
    ,RowType
FROM ProductProductHierarchy
LEFT OUTER JOIN Product ON Product.ProductID = ProductProductHierarchy.ItemProductID
    AND RowType = 1
LEFT OUTER JOIN ProductDetail ON ProductDetail.ProductDetailID = ProductProductHierarchy.ProductDetailID
    AND RowType = 2
LEFT OUTER JOIN ManufactoryOperation ON ManufactoryOperation.ManufactoryOperationID = ProductProductHierarchy.ManufactoryOperationID
    AND RowType = 3
LEFT OUTER JOIN Item ON Item.ItemID = ProductProductHierarchy.ItemID
    AND RowType = 4
OPTION (MAXRECURSION 0)

結束

Answer 1

看來您正在有效地構建一組異構行，但我通常會盡量避免這樣做。 如果需要，可以使用遞歸獲取產品樹，然后將操作，項目等作為單獨的結果集。 像這樣混合行類型很可能會引起麻煩（而不僅僅是性能問題）。

在不了解應用程序的全部功能的情況下，我無法說出應該從數據庫中檢索這些項目的最佳方法，但是我肯定會從那里開始作為一個可能的問題。