Então quer saber qual as 10 query mais pesada ?
Claro que você pode trocar o top 10 para top 5 e assim obter as 5 maiores
O order by 1 informa que estou usando a Media da CPU, poderia utilizar order by 4 para saber quais queries mais demoradas, etc..
E só seguir a logica.
select top 10 total_worker_time/execution_count as MediaCPU
, total_worker_time AS TotalCPU
, total_elapsed_time/execution_count as MediaDuration
, total_elapsed_time AS TotalDuration
, total_logical_reads/execution_count as MediaLogicalReads
, total_logical_reads AS TotalLogicalReads
, total_physical_reads/execution_count as MediaPhysicalReads
, total_physical_reads AS TotalPhysicalReads
, execution_count
, substring(st.text, (qs.statement_start_offset/2)+1
, ((case qs.statement_end_offset when -1 then datalength(st.text)
else qs.statement_end_offset
end - qs.statement_start_offset)/2) + 1) as txt
, query_plan
from sys.dm_exec_query_stats as qs
cross apply sys.dm_exec_sql_text(qs.sql_handle) as st
cross apply sys.dm_exec_query_plan (qs.plan_handle) as qp
order by 1 desc