SQL Server 2005 排查I/O瓶颈

-- top 10 引发i/o
SELECT (total_logical_reads/execution_count) AS avg_logical_reads
,(total_logical_writes/execution_count) AS avg_logical_writes
,(total_physical_reads/execution_count) AS avg_physical_reads
,execution_count
,(SELECT SUBSTRING(text,statement_start_offset/2 +1,
 (CASE WHEN statement_end_offset = -1
  THEN LEN(CONVERT(NVARCHAR(max),text)) *2
  ELSE statement_end_offset
  END - statement_start_offset)/2)
  FROM sys.dm_exec_sql_text(sql_handle)) AS query_text
FROM sys.dm_exec_query_stats
ORDER BY (total_logical_reads + total_logical_writes)