SQL Server Optimization

Optimization problems encountered on to record it, not going in-depth study database optimization

View statement execution efficiency

View the execution plan

Can be used directly display the estimated execution plan view, select statement, you can directly select the execution plan

Statement View

set statistics profile on 
set statistics io on 
set statistics time on 
go 

--两个go中间为你执行的sql语句
select * from Product p where exists (select id from JotrinDB.dbo.MarkingCode where PartNumber=p.ProductName and MarkingCode like '100%')

go 
set statistics profile off 
set statistics io off 
set statistics time off

Best not to use in, *

This is what I wrote SQL, there are two bad place

select * from Product where productName in (select PartNumber from JotrinDB.dbo.MarkingCode where MarkingCode like '100%')

1. In the process, remember not to use *
2. Best not to use in, change exists, and exists in the best kind of id field is indexed

sql statement following the completion of the following changes, what data to write, use exists judge id

select p.Name,p.Data from Product p where exists (select id from JotrinDB.dbo.MarkingCode where PartNumber=p.ProductName and MarkingCode like '100%')