SQL存储过程在SQL2008上的性能很好，但在SQL2005上却很差

Question

我有一个在运行<1sec的SQL2008服务器上开发的存储过程。 在另一台SQL2005服务器上，同一数据库上的相同sp需要大约1分钟。 如果不深入数据库模式的详细信息，谁能在此SP中看到任何明显的东西，而这可能会导致性能差异？ 可以使用CTE吗？ 还有其他选择吗？

编辑-我现在注意到，如果我直接在SQL 2005上运行SQL，它将在〜4秒内运行，但是执行SP仍需要一分钟以上的时间？ 看起来问题可能在SP执行中一样？？

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，它将在〜4秒内运行，但是执行SP仍需要一分钟以上的时间？

错误的参数嗅探然后：

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

SQL不良的存储过程执行计划性能-参数嗅探

参数嗅探在2005年很糟糕，但在2008年则更好。

Answer 2

你工会选择CalculatedMilestoneDate等于为NULL，不等于空。

这是多余的，只需从where子句中删除CalculatedMilestoneDate上的条件，就可以删除整个UNION。

除此之外，您应该验证两个数据库都定义了相同的索引。

-- 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

如果架构匹配，则可能是您缺少sql server 2005实例中的重要索引。 尝试运行sql服务器优化顾问并应用其索引建议。