可以用以下语句统计数据库的性能，需要注意的是必须用管理员的权限打开数据库才可以执行。
declare @n int set @n=30
;with maco as (
select top (@n)
plan_handle,
sum(total_worker_time) as total_worker_time ,
sum(execution_count) as execution_count ,
count(1) as sql_count
from sys.dm_exec_query_stats group by plan_handle
order by sum(total_worker_time) desc )
select t.text ,
a.total_worker_time ,
a.execution_count ,
a.sql_count
from maco a
cross apply sys.dm_exec_sql_text(plan_handle) t