Test the performance difference between sp_executesql and exec)

The expanded storage process of sp_executesql is similar to the Execute function of T-SQL, but it is slightly different that the execution plan executed through sp_executesql will be cached and can be reused. Test: NZ. perfectaction nzperfect@gmail.com The following test shows the performance differences between sp_executesql and exec. Create Database t_dbgouse t_dbgocreate table Tb (ID int identity (1, 1) primary key, name varchar (20 )) goinsert into TB select 'A' insert into TB select 'B' insert into TB select 'C' insert into TB select 'D' insert into TB select 'E' insert into TB select' f'go -- clear all the elements in the cache DBCC freeproccache -- view the select SQL as exec_ SQL cache used by the t_db database, objtype as exec_type, * from Master .. syscacheobjects where dbid = db_id ('t_db') and SQL like '% select * from TB where name %' and SQL not like '% syscacheobjects %' order by SQL results are empty,: -- Test exec, run the following SQL block declare @ SQL varchar (2000) Declare @ name varchar (20) declare @ I intset @ I = 1 while @ I <= 6 begin if @ I = 1 Set @ name = 'A' if @ I = 2 set @ name = 'B' if @ I = 3 set @ name = 'C' if @ I = 4 set @ name = 'D' if @ I = 5 set @ name = 'E' if @ I = 6 set @ name = 'F' set @ SQL = 'select * from TB where name = ''' + @ name + ''' exec (@ SQL) set @ I = @ I + 1end -- view the cache used by the t_db database select SQL as exec_ SQL, objtype as exec_type, * from master .. syscacheobjects where dbid = db_id ('t_db ') and SQL like '% select * from TB where name %' and SQL not like '% syscacheobjects %' order by SQL results have six records: for example, this indicates that SQL statements executed by SQL Server for exec use different caches even if the where field is the same but with different values. -- Test the execution of sp_executesql. Run the following SQL statement: declare @ SQL nvarchar (2000) Declare @ name nvarchar (20) declare @ I intset @ I = 1 while @ I <= 6 begin if @ I = 1 Set @ name = 'A' if @ I = 2 set @ name = 'B' if @ I = 3 set @ name = 'C' if @ I = 4 set @ name = 'D' if @ I = 5 set @ name = 'E' if @ I = 6 set @ name = 'F' set @ SQL = 'select * from TB where name = @ name' exec sp_executesql @ SQL, n' @ name nvarchar (20) ', @ name set @ I = @ I + 1end -- view the cache select SQL as exec_ SQL, Objtype as exec_type, * from Master .. syscacheobjects where dbid = db_id ('t_db ') and SQL like '% select * from TB where name %' and SQL not like '% syscacheobjects %' order by SQL results Add a record in addition to the preceding six records: for example, it indicates that SQL statements executed by SQL Server for sp_executesql do not need to be re-compiled if the where field is the same and the values are different, but the same cache plan is used for execution. -- Test completed: drop database t_dbgodrop table tbgoIn summary, the sp_executesql execution plan will be cached, but execute is not allowed. If a large number of repeated queries are performed, sp_executesql can improve the database performance better than execute.