SqlServer性能优化 即席查询(十三) – 孙丽媛 – 博客园 -Mikel

SqlServer性能优化 即席查询(十三) – 孙丽媛 – 博客园

2020年7月10日 分类: Debug, 数据库

来源: SqlServer性能优化 即席查询(十三) – 孙丽媛 – 博客园

执行计划,查询类别:

1.即席查询     2.预定义查询

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select c.EnglishProductCategoryName,p.EnglishProductName,p.Color,p.Size
from Product as p inner join ProductCategory as on p.ProductSubcategoryKey=
c.ProductCategoryKey where p.Size>'1'
<br>--查询执行计划是否被缓存
 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--清空执行计划
<br>--没有join 的形式会生成简单参数化
select EnglishProductName,Color,Size from Product where size>'1'--简单参数化<br><br>select EnglishProductName,Color,Size from Product where size>'2'--简单参数化

 

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select c.EnglishProductCategoryName,p.EnglishProductName,p.Color,p.Size
from Product as p inner join ProductCategory as on p.aProductSubcategoryKey=
c.ProductCategoryKey where p.Size>'2'

语句一样时即席查询才会重用执行计划。

 

优化:打开开关

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exec sp_configure 'show advanced options',1
reconfigure with override

为ad hoc的查询优化:

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exec sp_configure 'Optimize for ad hoc workloads',1
reconfigure with override

 

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--使用参数化
alter database HRDB
set Parameterization forced

set Parameterization forced 强制参数化(like无法识别 )

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select c.EnglishProductCategoryName,p.EnglishProductName,p.Color,p.Size
from Product as inner join ProductCategory as on p.ProductSubcategoryKey=
c.ProductCategoryKey where p.Size>'2'
select c.EnglishProductCategoryName,p.EnglishProductName,p.Color,p.Size
from Product as inner join ProductCategory as on p.ProductSubcategoryKey=
c.ProductCategoryKey where p.Size like '2%'

 

 

预定义查询:

预定义查询–参数化执行计划:

     存储过程:

           1.创建时延时检查

           2.第一次执行时编译并生成执行计划

           3.减少网络传输量

           4.封装变化点

           5.增强安全性,隔离访问控制

创建存储过程:

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create procedure p_querycp @size varchar(500)
as
select c.EnglishProductCategoryName,p.EnglishProductName,p.Color,p.size
from Product as inner join ProductCategory as on p.ProductSubcategoryKey=c.ProductCategoryKey
where p.Size>@size

做跟踪(以前有对应得截图):

执行存储过程:

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create procedure p_querycp @size varchar(500)
as
select c.EnglishProductCategoryName,p.EnglishProductName,p.Color,p.size
from Product as inner join ProductCategory as on p.ProductSubcategoryKey=c.ProductCategoryKey
where p.Size>@size
--清空执行计划
dbcc freeproccache
--执行
exec p_querycp '1'

执行重复的语句:

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dbcc freeproccache
exec p_querycp @size='1'
exec p_querycp @size='2'

查看缓存计划:

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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

 

预定义查询—参数化执行计划:

SP_ExecuteSql

避免了自己维护存储过程管理成本

可重用执行计划

Unicode字符串作为参数值与类型

大小写敏感

 

把存储过程定义成传递参数的:

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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'

 

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size 的大小换成  2

 

在.net中调用:(两种写法)

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public object getCp(string size)
{
    HRUser dbcontext = new HRUser();
    var cps = from in dbcontext.Product
              join in dbcontext.ProductCategory
              on p.ProductSubcategoryKey equals c.ProductCategoryKey
              where p.Size == size
              //返回匿名对象
              select new
              {
                  CName = c.EnglishProductCategoryName,
                  PName = p.EnglishProductName,
                  Color = p.Color,
                  Size = p.Size
              };
    return cps.ToList();
}<br>
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();
}

页面:

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<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
  <asp:Button ID="Button2" runat="server" OnClick="Button2_Click" Text="显示产品" />
  <asp:GridView ID="GridView1" runat="server">
  </asp:GridView>

点击后的事件:

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protected void Button2_Click(object sender, EventArgs e)
      {
          Product p = new Product();
          var cps = p.getCp(TextBox1.Text.Trim());
          GridView1.DataSource = cps;
          GridView1.DataBind();
      }

 

 

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--动态构建语句(执行带参数的方法)
 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+'''')
   

 

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dbcc freeproccache
--执行计划 缓存
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

形成两个缓存计划:

 

创建存储过程:

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create  procedure p_querye @vacationhours  int
as
select e.LoginID,e.JobTitle from EmployeeOp as where VacationHours>@vacationhours
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exec p_querye 2--实际执行计划 表扫描
exec p_querye 99--实际执行计划 表扫描 应用用索引更好

 

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--重新编译的执行计划
exec p_querycp 99 with recompile

 

手工的指定执行几乎:

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--手工的指定执行计划
exec  sp_create_plan_guide @name='执行任务计划指南之EmployeeOp Vacation',
--转成Unicode编码格式
@stmt=N'select e.LoginID,e.JobTitle from EmployeeOp as e where VacationHours>@vacationhours',
@type=N'Object',
--执行计划的名字
@module_or_batch ='p_querye',
@params =null,
--提示
@hints =N'OPTION(OPTIMIZE FOR(@vacationhours=''99''))'

 

清除执行计划:执行(会参考上面指定的执行计划)

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exec p_querye 2

存储过程重编译:

 

临时结果集:

定义跟踪的模板:

一:使用物理表进行临时结果集

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--1.做一张物理表
create procedure p_physicaltb
as
CREATE TABLE PhysicalTB(
    [SalesOrderID] [intNOT NULL,
    [SalesOrderDetailID] [int]  NOT NULL,
    [CarrierTrackingNumber] [nvarchar](25) NULL,
    [OrderQty] [smallintNOT NULL,
    [ProductID] [intNOT NULL,
    [SpecialOfferID] [intNOT 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

跟踪的情况:

 

删除之后再次创建执行。

物理表每次执行都会有重编译的过程(不建议使用物理表来存储临时结果集)

 

第二种方式:

临时表存储临时结果集

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create procedure p_temptb
as
CREATE TABLE #PhysicalTB(
    [SalesOrderID] [intNOT NULL,
    [SalesOrderDetailID] [int]  NOT NULL,
    [CarrierTrackingNumber] [nvarchar](25) NULL,
    [OrderQty] [smallintNOT NULL,
    [ProductID] [intNOT NULL,
    [SpecialOfferID] [intNOT 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

第一次执行时重新编译,第二次就不会重新编译了。

用到了tempdb临时表:

 

第三种方式:表变量存储临时结果集

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--表变量存储临时结果集
create procedure p_tabletb
as
--申明表变量
declare @PhysicalTB table(
    [SalesOrderID] [intNOT NULL,
    [SalesOrderDetailID] [int]  NOT NULL,
    [CarrierTrackingNumber] [nvarchar](25) NULL,
    [OrderQty] [smallintNOT NULL,
    [ProductID] [intNOT NULL,
    [SpecialOfferID] [intNOT 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

执行时不会重新编译

 

第四种方式:

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--CTE(通用表表达式)存储临时结果集  完全放在内存中 不会操作任何数据库中的东西
create procedure p_ctetb
as
begin
--会自动推断数据类型
;with PhysicalTB(
    [SalesOrderID],
    [SalesOrderDetailID],
    [CarrierTrackingNumber],
    [OrderQty] ,
    [ProductID],
    [SpecialOfferID],
    [UnitPrice] ,
    [UnitPriceDiscount] ,
    [LineTotal] ,
    [rowguid] ,
    [ModifiedDate]
as (select from OrderDetail)
--访问通用表表达式
select from PhysicalTB
end

跟踪的结果:

没有重新编译的过程,纯粹操作内存。tempdb数据库不会有任何的变化。

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set statistics time on
exec p_ctetb  --cpu:100  total:1300
set statistics time off
sp_helpdb 'tempdb'--17064,768

 

高版本的通用表达式可以进行多次的使用:

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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之前的数据库,只要把表达式在创建一次就可以了

 

临时数据集的优化处理:

 

 

优化查询:编译指南。

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--清空执行计划
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>
')  --表扫描
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 cross apply  sys.dm_exec_sql_text(c.plan_handle) as p
select from  sys.dm_exec_query_plan(0x06000A00CD253E14207CA0290200000001000000000000000000000000000000000000000000000000000000)

 


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备案信息冀ICP 0007948