MS SQL Server Query - IO 과점 쿼리

SELECT TOP 50
(qs.total_logical_reads + qs.total_logical_writes) /qs.execution_count as [Avg IO],
substring (qt.text,qs.statement_start_offset/2,
(case when qs.statement_end_offset = -1
then len(convert(nvarchar(max), qt.text)) * 2
else qs.statement_end_offset end - qs.statement_start_offset)/2)
as query_text,
qt.dbid,
qt.objectid
FROM sys.dm_exec_query_stats qs
cross apply sys.dm_exec_sql_text (qs.sql_handle) as qt
ORDER BY [Avg IO] DESC