SQL 存储过程性能在 SQL 2008 上很好，但在 SQL 2005 上很糟糕

Question

我有一个在运行

编辑 - 我现在注意到，如果我直接在 SQL 2005 上运行 SQL，它会在 ~4 秒内运行，但执行 SP 仍然需要一分钟？看起来问题可能出在 SP 执行中？？

CREATE PROCEDURE Workflow.GetTopTasks
    -- Add the parameters for the stored procedure here
    @ownerUserId int,
    @topN int = 10
AS
BEGIN
    -- SET NOCOUNT ON added to prevent extra result sets from
    -- interfering with SELECT statements.
    SET NOCOUNT ON;

    SET ROWCOUNT @topN;

    -- Insert statements for procedure here

WITH cteCalculatedDate (MilestoneDateId, CalculatedMilestoneDate)
AS
(
-- Anchor member definition
    SELECT  md.MilestoneDateId, md.SpecifiedDate
    FROM    Workflow.MilestoneDate md
    WHERE   md.RelativeMilestoneDateId IS NULL
UNION ALL
-- Recursive member definition
    SELECT md.MilestoneDateId, CalculatedMilestoneDate + md.RelativeDays
    FROM    Workflow.MilestoneDate md
            INNER JOIN cteCalculatedDate cte
                on md.RelativeMilestoneDateId = cte.MilestoneDateId
)

-- Statement that executes the CTE

    select 
        we.*
    from Workflow.WorkflowElement we
        left outer join cteCalculatedDate cte
            on cte.MilestoneDateId = we.DueDateId
        inner join Workflow.WorkflowInstance wi
            on wi.WorkflowInstanceId = we.WorkflowInstanceId
        left outer join Workflow.SchemeWorkflow sw
            on sw.WorkflowInstanceId = wi.WorkflowInstanceId
        left outer join Workflow.Scheme s
            on s.SchemeId = sw.SchemeId
        inner join Workflow.WorkflowDefinition wd
            on wd.WorkflowDefinitionId = wi.WorkflowDefinitionId
    where
        we.OwnerId = @ownerUserId           -- for given owner
        and we.CompletedDate is null        -- is not completed
        and we.ElementTypeId <= 4           -- is Action, Data, Decision or Document (Not End, Start or KeyDate)
        and cte.CalculatedMilestoneDate is not null -- has a duedate

    UNION

    select 
        we.*
    from Workflow.WorkflowElement we
        left outer join cteCalculatedDate cte
            on cte.MilestoneDateId = we.DueDateId
        inner join Workflow.WorkflowInstance wi
            on wi.WorkflowInstanceId = we.WorkflowInstanceId
        left outer join Workflow.SchemeWorkflow sw
            on sw.WorkflowInstanceId = wi.WorkflowInstanceId
        left outer join Workflow.Scheme s
            on s.SchemeId = sw.SchemeId
        inner join Workflow.WorkflowDefinition wd
            on wd.WorkflowDefinitionId = wi.WorkflowDefinitionId
    where
        we.OwnerId = @ownerUserId           -- for given owner
        and we.CompletedDate is null        -- is not completed
        and we.ElementTypeId <= 4           -- is Action, Data, Decision or Document (Not End, Start or KeyDate)
        and cte.CalculatedMilestoneDate is null -- does NOT have a duedate

    SET ROWCOUNT 0

END

Answer 1

编辑 - 我现在注意到，如果我 直接在 SQL 2005 上运行 SQL 运行约 4 秒，但执行 SP 还需要一分钟吗？？

然后是错误的参数嗅探：

http://elegantcode.com/2008/05/17/sql-parameter-sniffing-and-what-to-do-about-it/

SQL poor stored procedure execution plan performance - parameter sniffing

参数嗅探在 2005 年很糟糕，但在 2008 年更好。

Answer 2

您的工会选择CalculatedMilestoneDate 等于NULL 并且 不等于Null。

这是多余的，只需从 where 子句中删除 CalculatedMilestoneDate 上的条件即可删除整个 UNION。

除此之外，您应该验证两个数据库是否定义了相同的索引。

-- Statement that executes the CTE

    select 
        we.*
    from Workflow.WorkflowElement we
        left outer join cteCalculatedDate cte
            on cte.MilestoneDateId = we.DueDateId
        inner join Workflow.WorkflowInstance wi
            on wi.WorkflowInstanceId = we.WorkflowInstanceId
        left outer join Workflow.SchemeWorkflow sw
            on sw.WorkflowInstanceId = wi.WorkflowInstanceId
        left outer join Workflow.Scheme s
            on s.SchemeId = sw.SchemeId
        inner join Workflow.WorkflowDefinition wd
            on wd.WorkflowDefinitionId = wi.WorkflowDefinitionId
    where
        we.OwnerId = @ownerUserId           -- for given owner
        and we.CompletedDate is null        -- is not completed
        and we.ElementTypeId <= 4           -- is Action, Data, Decision or Document (Not End, Start or KeyDate)

Answer 3

如果模式匹配，那么您可能缺少 sql server 2005 实例中的重要索引。尝试运行 sql server 调优顾问并应用其索引建议。