set statistics io on
--清空缓存数据
dbcc dropcleanbuffers
go
--清空缓存计划
dbcc freeproccache
go
set statistics io on
go
select distinct Productid,unitprice from salesorderdetail_test where Productid=777
go
执行上面代码获取以下信息:
(4 row(s) affected)
Table 'Worktable'. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'SalesOrderDetail_Test'. Scan count 1, logical reads 481, physical reads 1, read-ahead reads 584, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
各数据详解:
1.Table
表的名称
2.scan count
执行的扫描次数
3.logical reads
从数据缓存读取的页数
4.physical reads
从磁盘读取的页数
5.read-ahead reads
为进行查询而预读入缓存的页数
6.lob logical reads
从数据缓存读取的Text,Ntext,Image或大值类型(Varchar(max),Nvarchar(max),Varbinary(max))页的数目
7.lob physical reads
从磁盘读取的Text,Ntext,Image或大值类型(Varchar(max),Nvarchar(max),Varbinary(max))页的数目
8.lob read-ahead reads
为进行查询而预读入缓存的Text,Ntext,Image或大值类型的页数