MSSQL执行计划重用
--简介
在Oracle的世界里有很多存储执行计划的手段如SQL_Profile, Stored_Outline, Plan_Baseline,在SQL Server里好像只有这样一个选择
--Ref
- 1. Batch Compilation, Recompilation, and Plan Caching Issues in SQL Server 2005
- 2.《SQL Server 2005 Practical Troubleshooting The Database Engine》Chapter 4 本页下方有一个使用例子是从这本书上摘录的
--自己创建执行计划
- 建立存储过程
代码
- sp_create_plan_guide
sp_create_plan_guide
@name = N ' Guide1 ' ,
@stmt = N ' SELECT *FROM Sales.SalesOrderHeader AS h,
Sales.Customer AS c,
Sales.SalesTerritory AS t
WHERE h.CustomerID = c.CustomerID
AND c.TerritoryID = t.TerritoryID
AND CountryRegionCode = @Country_region ' ,
@type = N ' OBJECT ' ,
@module_or_batch = N ' Sales.GetSalesOrderByCountry ' ,
@params = NULL ,
@hints = N ' OPTION (OPTIMIZE FOR (@Country_region = N '' US '' )) '
-- 其中@Country_region = N''US''查询较多，所以以下plan把us为参数的语句放到缓存Buffer中
@hints = N ' OPTION (PARAMETERIZATION FORCED) '
-- 其中PARAMETERIZATION FORCED把带参数所有语句都放到缓存Buffer中 - sp_get_query_template:按照特定的语句生成template,之后生成执行计划
-- Obtain the paramaterized form of the query:
DECLARE @stmt nvarchar ( max );
DECLARE @params nvarchar ( max );
EXEC sp_get_query_template N ' SELECT pi.ProductID, SUM(pi.Quantity) AS Total
FROM Production.ProductModel pm
INNER JOIN Production.ProductInventory pi
ON pm.ProductModelID = pi.ProductID
WHERE pi.ProductID = 101
GROUP BY pi.ProductID, pi.Quantity
HAVING SUM(pi.Quantity) > 50 ' ,
@stmt OUTPUT,
@params OUTPUT;
-- Force parameterization of the query. (This step is only required
-- if the query is not already being parameterized.)
EXEC sp_create_plan_guide N ' TemplateGuide1 ' ,
@stmt ,
N ' TEMPLATE ' ,
NULL ,
@params ,
N ' OPTION(PARAMETERIZATION FORCED) ' ;
-- Create a plan guide on the parameterized query
EXEC sp_create_plan_guide N ' GeneralizedGuide1 ' ,
@stmt ,
N ' SQL ' ,
NULL ,
@params ,
N ' OPTION(HASH JOIN) ' ; -- 强制进行Hash Join
--从缓存(sys.dm_exec_query_stats)中的查询计划内创建执行计划
- sp_create_plan_guide_from_handle
USE AdventureWorks;
GO
SELECT WorkOrderID, p.Name, OrderQty, DueDate
FROM Production.WorkOrder AS w
JOIN Production.Product AS p ON w.ProductID = p.ProductID
WHERE p.ProductSubcategoryID > 4
ORDER BY p.Name, DueDate;
GO
-- Inspect the query plan by using dynamic management views.
SELECT * FROM sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_sql_text(sql_handle)
CROSS APPLY sys.dm_exec_text_query_plan(qs.plan_handle, qs.statement_start_offset, qs.statement_end_offset) AS qp
WHERE text LIKE N ' SELECT WorkOrderID, p.Name, OrderQty, DueDate% ' ;
GO
-- Create a plan guide for the query by specifying the query plan in the plan cache.
DECLARE @plan_handle varbinary ( 64 );
DECLARE @offset int ;
SELECT @plan_handle = plan_handle, @offset = qs.statement_start_offset
FROM sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_sql_text(sql_handle) AS st
CROSS APPLY sys.dm_exec_text_query_plan(qs.plan_handle, qs.statement_start_offset, qs.statement_end_offset) AS qp
WHERE text LIKE N ' SELECT WorkOrderID, p.Name, OrderQty, DueDate% ' ;
EXECUTE sp_create_plan_guide_from_handle
@name = N ' Guide1 ' ,
@plan_handle = @plan_handle ,
@statement_start_offset = @offset ;
GO
-- Verify that the plan guide is created.
SELECT * FROM sys.plan_guides
WHERE scope_batch LIKE N ' SELECT WorkOrderID, p.Name, OrderQty, DueDate% ' ;
GO - 为多语句批处理创建多个计划指南
USE AdventureWorks;
GO
SELECT * FROM Production.Product WHERE ProductSubcategoryID > 4 ;
SELECT * FROM Person.Address;
SELECT * FROM Production.Product WHERE ProductSubcategoryID > 10 ;
GO
-- Examine the query plans for this batch
SELECT * FROM sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_sql_text(sql_handle)
CROSS APPLY sys.dm_exec_text_query_plan(qs.plan_handle, qs.statement_start_offset, qs.statement_end_offset) AS qp
WHERE text LIKE N ' SELECT * FROM Production.Product WHERE ProductSubcategoryID > 4% ' ;
GO
-- Create plan guides for the first and third statements in the batch by specifying the statement offsets.
BEGIN TRANSACTION
DECLARE @plan_handle varbinary ( 64 );
DECLARE @offset int ;
SELECT @plan_handle = plan_handle, @offset = qs.statement_start_offset
FROM sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_sql_text(sql_handle) AS st
CROSS APPLY sys.dm_exec_text_query_plan(qs.plan_handle, qs.statement_start_offset, qs.statement_end_offset) AS qp
WHERE text LIKE N ' SELECT * FROM Production.Product WHERE ProductSubcategoryID > 4% '
AND SUBSTRING (st. text , (qs.statement_start_offset / 2 ) + 1 ,
(( CASE statement_end_offset
WHEN - 1 THEN DATALENGTH (st. text )
ELSE qs.statement_end_offset END
- qs.statement_start_offset) / 2 ) + 1 ) like ' SELECT * FROM Production.Product WHERE ProductSubcategoryID > 4% '
EXECUTE sp_create_plan_guide_from_handle
@name = N ' Guide_Statement1_only ' ,
@plan_handle = @plan_handle ,
@statement_start_offset = @offset ;
SELECT @plan_handle = plan_handle, @offset = qs.statement_start_offset
FROM sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_sql_text(sql_handle) AS st
CROSS APPLY sys.dm_exec_text_query_plan(qs.plan_handle, qs.statement_start_offset, qs.statement_end_offset) AS qp
WHERE text LIKE N ' SELECT * FROM Production.Product WHERE ProductSubcategoryID > 4% '
AND SUBSTRING (st. text , (qs.statement_start_offset / 2 ) + 1 ,
(( CASE statement_end_offset
WHEN - 1 THEN DATALENGTH (st. text )
ELSE qs.statement_end_offset END
- qs.statement_start_offset) / 2 ) + 1 ) like ' SELECT * FROM Production.Product WHERE ProductSubcategoryID > 10% '
EXECUTE sp_create_plan_guide_from_handle
@name = N ' Guide_Statement3_only ' ,
@plan_handle = @plan_handle ,
@statement_start_offset = @offset ;
COMMIT TRANSACTION
GO
-- Verify the plan guides are created.
SELECT * FROM sys.plan_guides;
GO
--删除,启用或禁用执行计划
- 删除、启用或禁用计划指南 -- sp_control_plan_guide
-- Create a procedure on which to define the plan guide.
IF OBJECT_ID (N ' Sales.GetSalesOrderByCountry ' , N ' P ' ) IS NOT NULL
DROP PROCEDURE Sales.GetSalesOrderByCountry;
GO
CREATE PROCEDURE Sales.GetSalesOrderByCountry
( @Country nvarchar ( 60 ))
AS
BEGIN
SELECT *
FROM Sales.SalesOrderHeader AS h
INNER JOIN Sales.Customer AS c ON h.CustomerID = c.CustomerID
INNER JOIN Sales.SalesTerritory AS t ON c.TerritoryID = t.TerritoryID
WHERE t.CountryRegionCode = @Country ;
END
GO
-- Create the plan guide.
EXEC sp_create_plan_guide N ' Guide3 ' ,
N ' SELECT *
FROM Sales.SalesOrderHeader AS h
INNER JOIN Sales.Customer AS c ON h.CustomerID = c.CustomerID
INNER JOIN Sales.SalesTerritory AS t ON c.TerritoryID = t.TerritoryID
WHERE t.CountryRegionCode = @Country ' ,
N ' OBJECT ' ,
N ' Sales.GetSalesOrderByCountry ' ,
NULL ,
N ' OPTION (OPTIMIZE FOR (@Country = N '' US '' )) ' ;
GO
-- Disable the plan guide.
EXEC sp_control_plan_guide N ' DISABLE ' , N ' Guide3 ' ;
GO
-- Enable the plan guide.
EXEC sp_control_plan_guide N ' ENABLE ' , N ' Guide3 ' ;
GO
-- Drop the plan guide.
EXEC sp_control_plan_guide N ' DROP ' , N ' Guide3 ' ; - 禁用当前数据库中的所有计划指南
USE AdventureWorks;
GO
EXEC sp_control_plan_guide N ' DISABLE ALL ' ;
--一个例子(忘了是从哪里看到的,没修改就放到这里了)
- 1 制造分散数据
代码
- 2 开始测试
采用上述的作法直接影响SQL SERVER编译执行计划的方式，但如同各种数据表提示（hint），非得不得已不要轻易使用；使用上述查询计划，适用1，但用户又偏好2，则上述配置则反而有害了；DBCC FREEPROCCACHE
SET STATISTICS IO ON
SET STATISTICS TIME ON
EXEC sp 2
/* SQL Server 分析和编译时间:CPU 时间 = 0 毫秒，占用时间 = 1 毫秒。
SQL Server 分析和编译时间:CPU 时间 = 0 毫秒，占用时间 = 2 毫秒。
表 't'。扫描计数 1，逻辑读取 6 次，物理读取 0 次，预读 0 次，lob 逻辑读取 0 次，lob 物理读取 0 次，lob 预读 0 次。
SQL Server 执行时间:CPU 时间 = 0 毫秒，占用时间 = 1 毫秒。
SQL Server 执行时间:CPU 时间 = 0 毫秒，占用时间 = 2 毫秒。
*/
EXEC sp 2
/* SQL Server 分析和编译时间:CPU 时间 = 0 毫秒，占用时间 = 1 毫秒。
SQL Server 分析和编译时间:CPU 时间 = 0 毫秒，占用时间 = 2 毫秒。
表 't'。扫描计数 1，逻辑读取 786890 次，物理读取 0 次，预读 0 次，lob 逻辑读取 0 次，lob 物理读取 0 次，lob 预读 0 次。
SQL Server 执行时间:CPU 时间 = 0 毫秒，占用时间 = 1 毫秒。
SQL Server 执行时间:CPU 时间 = 0 毫秒，占用时间 = 2 毫秒。
*/
Alter proc sp @i int as select c2,c3 from t where c2 = @i Option (Optimize for ( @i = 1 ));
EXEC sp_create_plan_guide
@Name = N ' Guide1 ' ,
@stmt = N ' SELECT c2,c3 FROM t WHERE c2=@i ' ,
@type = N ' OBJECT ' ,
@module_or_batch = N ' dbo.sp ' ,
@params = NULL ,
@hints = N ' OPTION (OPTIMIZE FOR (@i = 1)) '
GO
SET SHOWPLAN_XML ON ;
GO
select c2,c3 from t where c2 = 1
go
SET SHOWPLAN_XML OFF ;
--在查询配置中，直接使用该查询计划，如：
EXEC sp_create_plan_guide @Name = N ' Guide1 ' ,
@stmt = N ' SELECT c2,c3 FROM t WHERE c2=@i ' ,
@type = N ' OBJECT ' ,
@module_or_batch = N ' dbo.sp ' ,
@params = NULL ,
@hints = N ' OPTION (USE PLAN
N ' 上一个脚本的XML结果 ' ) '