Sql server 不同参数值的不同执行计划

查询1运行速度快，并使用并行执行计划

SELECT c.[Date]
FROM Table1 c
left join Table2 bec on bec.Col1ID = c.Col1ID and bec.Active = 1
WHERE c.Active = 1
AND (c.Col2ID not in (3,4,5,6,7,8,9,10) or c.Col2ID is null) 
and (c.[Date] >= '06/12/2014 02:30:00.000 PM') 

SELECT c.[Date]
FROM Table1 c
left join Table2 bec on bec.Col1ID = c.Col1ID and bec.Active = 1
WHERE c.Active = 1
AND (c.Col2ID not in (3,4,5,6,7,8,9,10) or c.Col2ID is null) 
and (c.[Date] >= '06/15/2014 02:30:00.000 PM') 

查询2需要更长的时间，并使用正常（串行）执行计划

SELECT c.[Date]
FROM Table1 c
left join Table2 bec on bec.Col1ID = c.Col1ID and bec.Active = 1
WHERE c.Active = 1
AND (c.Col2ID not in (3,4,5,6,7,8,9,10) or c.Col2ID is null) 
and (c.[Date] >= '06/12/2014 02:30:00.000 PM') 

SELECT c.[Date]
FROM Table1 c
left join Table2 bec on bec.Col1ID = c.Col1ID and bec.Active = 1
WHERE c.Active = 1
AND (c.Col2ID not in (3,4,5,6,7,8,9,10) or c.Col2ID is null) 
and (c.[Date] >= '06/15/2014 02:30:00.000 PM') 

问题:

Query2正在尝试获取Query1的子集数据，因此Query2应该更快

这两个查询只因参数值不同而不同，因此为什么执行计划完全不同呢

关于服务器的信息：这是在SQL Server 2008中运行的

表结构如下：

TABLE Table1(
       Col1Id [int] IDENTITY(1,1) NOT NULL,
       Col2Id [int] NULL,
       Col3 [int] NOT NULL,
       Col4 [int] NULL,
       Active [bit] NOT NULL
       [Date] [datetime] NOT NULL)

表1的索引 非群集开启（活动，日期）

表2的索引 包括[Active]上的非群集（列，列1ID） 聚集在（Col，Col1ID）

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欢迎对此提供任何帮助。

尝试将包含的列添加到Table1索引中，并在Table2上创建新索引。另外，确保统计数据是最新的

CREATE INDEX idx_Table1_Active_Date ON dbo.Table1 (Active, Date) INCLUDE (Col1Id, Col2Id);
CREATE INDEX idx_Table2_Col1ID_Active ON dbo.Table2 (Col1ID, Active);

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你的桌子结构会很有帮助。还有你的索引。我刚刚更新了问题，Query1并行运行，Query2串行运行。如果需要静止表结构，请告诉我。是的。当然，帕特里克，我会在几分钟内更新这个问题。我不能马上做，因为我不能透露确切的表名和列名。公司政策：（。