執行計划,查詢類別:
1.即席查詢 2.預定義查詢
select c.EnglishProductCategoryName,p.EnglishProductName,p.Color,p.Size from Product as p inner join ProductCategory as c on p.ProductSubcategoryKey= c.ProductCategoryKey where p.Size>'1'
--查詢執行計划是否被緩存 select c.usecounts,c.size_in_bytes,c.objtype,t.text from sys.dm_exec_cached_plans as c cross apply sys.dm_exec_sql_text(c.plan_handle) as t dbcc freeproccache--清空執行計划
--沒有join 的形式會生成簡單參數化 select EnglishProductName,Color,Size from Product where size>'1'--簡單參數化
select EnglishProductName,Color,Size from Product where size>'2'--簡單參數化
select c.EnglishProductCategoryName,p.EnglishProductName,p.Color,p.Size from Product as p inner join ProductCategory as c on p.aProductSubcategoryKey= c.ProductCategoryKey where p.Size>'2'
語句一樣時即席查詢才會重用執行計划。
優化:打開開關
exec sp_configure 'show advanced options',1 reconfigure with override
為ad hoc的查詢優化:
exec sp_configure 'Optimize for ad hoc workloads',1 reconfigure with override
--使用參數化 alter database HRDB set Parameterization forced
set Parameterization forced 強制參數化(like無法識別 )
select c.EnglishProductCategoryName,p.EnglishProductName,p.Color,p.Size from Product as p inner join ProductCategory as c on p.ProductSubcategoryKey= c.ProductCategoryKey where p.Size>'2' select c.EnglishProductCategoryName,p.EnglishProductName,p.Color,p.Size from Product as p inner join ProductCategory as c on p.ProductSubcategoryKey= c.ProductCategoryKey where p.Size like '2%'
預定義查詢:
預定義查詢--參數化執行計划:
存儲過程:
1.創建時延時檢查
2.第一次執行時編譯並生成執行計划
3.減少網絡傳輸量
4.封裝變化點
5.增強安全性,隔離訪問控制
創建存儲過程:
create procedure p_querycp @size varchar(500) as select c.EnglishProductCategoryName,p.EnglishProductName,p.Color,p.size from Product as p inner join ProductCategory as c on p.ProductSubcategoryKey=c.ProductCategoryKey where p.Size>@size
做跟蹤(以前有對應得截圖):
執行存儲過程:
create procedure p_querycp @size varchar(500) as select c.EnglishProductCategoryName,p.EnglishProductName,p.Color,p.size from Product as p inner join ProductCategory as c on p.ProductSubcategoryKey=c.ProductCategoryKey where p.Size>@size --清空執行計划 dbcc freeproccache --執行 exec p_querycp '1'
執行重復的語句:
dbcc freeproccache exec p_querycp @size='1' exec p_querycp @size='2'
查看緩存計划:
select c.usecounts,c.size_in_bytes,c.objtype,t.text from sys.dm_exec_cached_plans as c cross apply sys.dm_exec_sql_text(c.plan_handle) as t
預定義查詢---參數化執行計划:
SP_ExecuteSql
避免了自己維護存儲過程管理成本
可重用執行計划
Unicode字符串作為參數值與類型
大小寫敏感
把存儲過程定義成傳遞參數的:
declare @sqltext nvarchar(500) set @sqltext=N' select c.EnglishProductCategoryName,p.EnglishProductName,p.Color,p.size from Product as p inner join ProductCategory as c on p.ProductSubcategoryKey=c.ProductCategoryKey where p.Size>@size ' declare @params nvarchar(500) set @params=N'@size varchar(500)' exec sp_executesql @sqltext,@params,@size='1'
把size 的大小換成 2
在.net中調用:(兩種寫法)
public object getCp(string size) { HRUser dbcontext = new HRUser(); var cps = from p in dbcontext.Product join c in dbcontext.ProductCategory on p.ProductSubcategoryKey equals c.ProductCategoryKey where p.Size == size //返回匿名對象 select new { CName = c.EnglishProductCategoryName, PName = p.EnglishProductName, Color = p.Color, Size = p.Size }; return cps.ToList(); }
public object getcp(string size) { HRUser dbcontext = new HRUser(); var cps = dbcontext.Product.Join(dbcontext.ProductCategory, a => a.ProductSubcategoryKey, ar => ar.ProductCategoryKey, (a, ar) => new { CName = ar.EnglishProductCategoryName, PName = a.EnglishProductName, Color = a.Color, Size = a.Size }).Where(p => p.Size == size); return cps.ToList(); }
頁面:
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox> <asp:Button ID="Button2" runat="server" OnClick="Button2_Click" Text="顯示產品" /> <asp:GridView ID="GridView1" runat="server"> </asp:GridView>
點擊后的事件:
protected void Button2_Click(object sender, EventArgs e) { Product p = new Product(); var cps = p.getCp(TextBox1.Text.Trim()); GridView1.DataSource = cps; GridView1.DataBind(); }
--動態構建語句(執行帶參數的方法) declare @size varchar(500) set @size='2' execute('select c.EnglishProductCategoryName,p.EnglishProductName,p.Color,p.size from Product as p inner join ProductCategory as c on p.ProductSubcategoryKey=c.ProductCategoryKey where p.Size>'+''''+@size+'''')
dbcc freeproccache --執行計划 緩存 select c.usecounts,c.size_in_bytes,c.objtype,t.text from sys.dm_exec_cached_plans as c cross apply sys.dm_exec_sql_text(c.plan_handle) as t
形成兩個緩存計划:
創建存儲過程:
create procedure p_querye @vacationhours int as select e.LoginID,e.JobTitle from EmployeeOp as e where VacationHours>@vacationhours
exec p_querye 2--實際執行計划 表掃描 exec p_querye 99--實際執行計划 表掃描 應用用索引更好
--重新編譯的執行計划 exec p_querycp 99 with recompile
手工的指定執行幾乎:
--手工的指定執行計划 exec sp_create_plan_guide @name='執行任務計划指南之EmployeeOp Vacation', --轉成Unicode編碼格式 @stmt=N'select e.LoginID,e.JobTitle from EmployeeOp as e where VacationHours>@vacationhours', @type=N'Object', --執行計划的名字 @module_or_batch ='p_querye', @params =null, --提示 @hints =N'OPTION(OPTIMIZE FOR(@vacationhours=''99''))'
清除執行計划:執行(會參考上面指定的執行計划)
exec p_querye 2
存儲過程重編譯:
臨時結果集:
定義跟蹤的模板:
一:使用物理表進行臨時結果集
--1.做一張物理表 create procedure p_physicaltb as CREATE TABLE PhysicalTB( [SalesOrderID] [int] NOT NULL, [SalesOrderDetailID] [int] NOT NULL, [CarrierTrackingNumber] [nvarchar](25) NULL, [OrderQty] [smallint] NOT NULL, [ProductID] [int] NOT NULL, [SpecialOfferID] [int] NOT NULL, [UnitPrice] [money] NOT NULL, [UnitPriceDiscount] [money] NOT NULL, [LineTotal] [numeric](38, 6) NOT NULL, [rowguid] [uniqueidentifier] NOT NULL, [ModifiedDate] [datetime] NOT NULL ) insert into PhysicalTB select * from OrderDetail select * from PhysicalTB set statistics time on exec p_physicaltb --cpu:391 total:1762 set statistics time off
跟蹤的情況:
刪除之后再次創建執行。
物理表每次執行都會有重編譯的過程(不建議使用物理表來存儲臨時結果集)
第二種方式:
臨時表存儲臨時結果集
create procedure p_temptb as CREATE TABLE #PhysicalTB( [SalesOrderID] [int] NOT NULL, [SalesOrderDetailID] [int] NOT NULL, [CarrierTrackingNumber] [nvarchar](25) NULL, [OrderQty] [smallint] NOT NULL, [ProductID] [int] NOT NULL, [SpecialOfferID] [int] NOT NULL, [UnitPrice] [money] NOT NULL, [UnitPriceDiscount] [money] NOT NULL, [LineTotal] [numeric](38, 6) NOT NULL, [rowguid] [uniqueidentifier] NOT NULL, [ModifiedDate] [datetime] NOT NULL ) insert into #PhysicalTB select * from OrderDetail select * from #PhysicalTB drop table #PhysicalTB set statistics time on exec p_temptb --cpu:110 total:1494 set statistics time off sp_helpdb 'tempdb'--16064,768
第一次執行時重新編譯,第二次就不會重新編譯了。
用到了tempdb臨時表:
第三種方式:表變量存儲臨時結果集
--表變量存儲臨時結果集 create procedure p_tabletb as --申明表變量 declare @PhysicalTB table( [SalesOrderID] [int] NOT NULL, [SalesOrderDetailID] [int] NOT NULL, [CarrierTrackingNumber] [nvarchar](25) NULL, [OrderQty] [smallint] NOT NULL, [ProductID] [int] NOT NULL, [SpecialOfferID] [int] NOT NULL, [UnitPrice] [money] NOT NULL, [UnitPriceDiscount] [money] NOT NULL, [LineTotal] [numeric](38, 6) NOT NULL, [rowguid] [uniqueidentifier] NOT NULL, [ModifiedDate] [datetime] NOT NULL ) insert into @PhysicalTB select * from OrderDetail select * from @PhysicalTB set statistics time on exec p_tabletb --cpu:110 total:1494 set statistics time off sp_helpdb 'tempdb'--17064,768
執行時不會重新編譯
第四種方式:
--CTE(通用表表達式)存儲臨時結果集 完全放在內存中 不會操作任何數據庫中的東西 create procedure p_ctetb as begin --會自動推斷數據類型 ;with PhysicalTB( [SalesOrderID], [SalesOrderDetailID], [CarrierTrackingNumber], [OrderQty] , [ProductID], [SpecialOfferID], [UnitPrice] , [UnitPriceDiscount] , [LineTotal] , [rowguid] , [ModifiedDate] ) as (select * from OrderDetail) --訪問通用表表達式 select * from PhysicalTB end
跟蹤的結果:
沒有重新編譯的過程,純粹操作內存。tempdb數據庫不會有任何的變化。
set statistics time on exec p_ctetb --cpu:100 total:1300 set statistics time off sp_helpdb 'tempdb'--17064,768
高版本的通用表達式可以進行多次的使用:
create procedure p_ctetb1 as begin ;with PhysicalTB( [SalesOrderID], [SalesOrderDetailID], [CarrierTrackingNumber], [OrderQty] , [ProductID], [SpecialOfferID], [UnitPrice] , [UnitPriceDiscount] , [LineTotal] , [rowguid] , [ModifiedDate] ) as (select * from OrderDetail) select * from PhysicalTB select * from PhysicalTB end exec p_ctetb1
08之前的數據庫,只要把表達式在創建一次就可以了
臨時數據集的優化處理:
優化查詢:編譯指南。
--清空執行計划 dbcc freeproccache select * from EmployeeOp where VacationHours>1 option(use plan N' <ShowPlanXML xmlns="http://schemas.microsoft.com/sqlserver/2004/07/showplan" Version="1.2" Build="12.0.2000.8"> <BatchSequence> <Batch> <Statements> <StmtSimple StatementText="select * from EmployeeOp where VacationHours>99" StatementId="1" StatementCompId="1" StatementType="SELECT" RetrievedFromCache="true" StatementSubTreeCost="0.00657038" StatementEstRows="1" StatementOptmLevel="FULL" QueryHash="0x7E06C77E90EB9FBB" QueryPlanHash="0x64478FC6152D2A83" StatementOptmEarlyAbortReason="GoodEnoughPlanFound" CardinalityEstimationModelVersion="120" ParameterizedText="(@1 tinyint)SELECT * FROM [EmployeeOp] WHERE [VacationHours]>@1"> <StatementSetOptions QUOTED_IDENTIFIER="true" ARITHABORT="true" CONCAT_NULL_YIELDS_NULL="true" ANSI_NULLS="true" ANSI_PADDING="true" ANSI_WARNINGS="true" NUMERIC_ROUNDABORT="false" /> <QueryPlan CachedPlanSize="40" CompileTime="6" CompileCPU="6" CompileMemory="232"> <MemoryGrantInfo SerialRequiredMemory="0" SerialDesiredMemory="0" /> <OptimizerHardwareDependentProperties EstimatedAvailableMemoryGrant="206857" EstimatedPagesCached="51714" EstimatedAvailableDegreeOfParallelism="2" /> <RelOp NodeId="0" PhysicalOp="Nested Loops" LogicalOp="Inner Join" EstimateRows="1" EstimateIO="0" EstimateCPU="4.18e-006" AvgRowSize="830" EstimatedTotalSubtreeCost="0.00657038" Parallel="0" EstimateRebinds="0" EstimateRewinds="0" EstimatedExecutionMode="Row"> <OutputList> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="BusinessEntityID" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="NationalIDNumber" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="LoginID" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="OrganizationNode" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="OrganizationLevel" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="JobTitle" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="BirthDate" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="MaritalStatus" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="Gender" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="HireDate" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="SalariedFlag" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="VacationHours" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="SickLeaveHours" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="CurrentFlag" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="rowguid" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="ModifiedDate" /> </OutputList> <NestedLoops Optimized="0"> <OuterReferences> <ColumnReference Column="Bmk1000" /> </OuterReferences> <RelOp NodeId="1" PhysicalOp="Index Seek" LogicalOp="Index Seek" EstimateRows="1" EstimateIO="0.003125" EstimateCPU="0.0001581" AvgRowSize="19" EstimatedTotalSubtreeCost="0.0032831" TableCardinality="290" Parallel="0" EstimateRebinds="0" EstimateRewinds="0" EstimatedExecutionMode="Row"> <OutputList> <ColumnReference Column="Bmk1000" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="VacationHours" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="SickLeaveHours" /> </OutputList> <IndexScan Ordered="1" ScanDirection="FORWARD" ForcedIndex="0" ForceSeek="0" ForceScan="0" NoExpandHint="0" Storage="RowStore"> <DefinedValues> <DefinedValue> <ColumnReference Column="Bmk1000" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="VacationHours" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="SickLeaveHours" /> </DefinedValue> </DefinedValues> <Object Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Index="[nc_Employee_vacationsickleave]" IndexKind="NonClustered" Storage="RowStore" /> <SeekPredicates> <SeekPredicateNew> <SeekKeys> <StartRange ScanType="GT"> <RangeColumns> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="VacationHours" /> </RangeColumns> <RangeExpressions> <ScalarOperator ScalarString="(99)"> <Const ConstValue="(99)" /> </ScalarOperator> </RangeExpressions> </StartRange> </SeekKeys> </SeekPredicateNew> </SeekPredicates> </IndexScan> </RelOp> <RelOp NodeId="3" PhysicalOp="RID Lookup" LogicalOp="RID Lookup" EstimateRows="1" EstimateIO="0.003125" EstimateCPU="0.0001581" AvgRowSize="826" EstimatedTotalSubtreeCost="0.0032831" TableCardinality="290" Parallel="0" EstimateRebinds="0" EstimateRewinds="0" EstimatedExecutionMode="Row"> <OutputList> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="BusinessEntityID" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="NationalIDNumber" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="LoginID" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="OrganizationNode" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="OrganizationLevel" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="JobTitle" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="BirthDate" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="MaritalStatus" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="Gender" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="HireDate" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="SalariedFlag" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="CurrentFlag" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="rowguid" /> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="ModifiedDate" /> </OutputList> <IndexScan Lookup="1" Ordered="1" ScanDirection="FORWARD" ForcedIndex="0" ForceSeek="0" ForceScan="0" NoExpandHint="0" Storage="RowStore"> <DefinedValues> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="BusinessEntityID" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="NationalIDNumber" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="LoginID" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="OrganizationNode" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="OrganizationLevel" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="JobTitle" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="BirthDate" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="MaritalStatus" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="Gender" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="HireDate" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="SalariedFlag" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="CurrentFlag" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="rowguid" /> </DefinedValue> <DefinedValue> <ColumnReference Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" Column="ModifiedDate" /> </DefinedValue> </DefinedValues> <Object Database="[HRDB]" Schema="[dbo]" Table="[EmployeeOp]" TableReferenceId="-1" IndexKind="Heap" Storage="RowStore" /> <SeekPredicates> <SeekPredicateNew> <SeekKeys> <Prefix ScanType="EQ"> <RangeColumns> <ColumnReference Column="Bmk1000" /> </RangeColumns> <RangeExpressions> <ScalarOperator ScalarString="[Bmk1000]"> <Identifier> <ColumnReference Column="Bmk1000" /> </Identifier> </ScalarOperator> </RangeExpressions> </Prefix> </SeekKeys> </SeekPredicateNew> </SeekPredicates> </IndexScan> </RelOp> </NestedLoops> </RelOp> <ParameterList> <ColumnReference Column="@1" ParameterCompiledValue="(99)" /> </ParameterList> </QueryPlan> </StmtSimple> </Statements> </Batch> </BatchSequence> </ShowPlanXML> ') --表掃描 select * from sys.dm_exec_cached_plans select * from sys.dm_exec_sql_text select * from sys.dm_exec_query_plan select * from EmployeeOp where VacationHours>99 -- 索引 select c.plan_handle,p.text from sys.dm_exec_cached_plans as c cross apply sys.dm_exec_sql_text(c.plan_handle) as p select * from sys.dm_exec_query_plan(0x06000A00CD253E14207CA0290200000001000000000000000000000000000000000000000000000000000000)