SQL存储过程性能很好SQL2008，但在SQL2005很糟糕

Question

我有一个存储过程，我已经开发了SQL2008服务器上运行< 1秒。在另一台SQL2005服务器上，同一个数据库上的同一个服务器需要大约1分钟的时间。没有深入了解数据库模式的细节，任何人都可以在此SP中看到任何可能导致此性能差异的显而易见的内容？这可能是CTE的使用吗？有其他选择吗？

编辑 - 我现在已经注意到，如果我直接在SQL 2005上运行SQL它运行在〜4secs但执行SP仍需要一分钟？看起来问题可能会在SP执行？

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

您的工会正在选择CalculatedMilestoneDate等于NULL 和不等于Null。

这是多余的，只需从where子句中去除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具有相同的索引定义。

-- 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 2

如果模式匹配，那么你可能在sql server 2005实例中缺少重要的索引。尝试运行sql server调优顾问并应用其索引建议。

Answer 3

编辑 - 我现在已经注意到，如果我 对SQL直接运行SQL中〜4secs 2005年，它 运行，但执行SP 仍然需要一分钟？

错误的参数嗅探则：2005年

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

SQL poor stored procedure execution plan performance - parameter sniffing

参数嗅探很糟糕，但在2008年