性能调优汇总

--查看运行的sql语句的运行情况

SELECT  creation_time  N'语句编译时间'
        ,last_execution_time  N'上次执行时间'
        ,total_physical_reads N'物理读取总次数'
        ,total_logical_reads/execution_count N'每次逻辑读次数'
        ,total_logical_reads  N'逻辑读取总次数'
        ,total_logical_writes N'逻辑写入总次数'
        , execution_count  N'执行次数'
        , total_worker_time/1000 N'所用的CPU总时间ms'
        , total_elapsed_time/1000  N'总花费时间ms'
        , (total_elapsed_time / execution_count)/1000  N'平均时间ms'
        ,SUBSTRING(st.text, (qs.statement_start_offset/2) + 1,
         ((CASE statement_end_offset
          WHEN -1 THEN DATALENGTH(st.text)
          ELSE qs.statement_end_offset END
            - qs.statement_start_offset)/2) + 1) N'执行语句'
FROM sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) st
where SUBSTRING(st.text, (qs.statement_start_offset/2) + 1,
         ((CASE statement_end_offset
          WHEN -1 THEN DATALENGTH(st.text)
          ELSE qs.statement_end_offset END
            - qs.statement_start_offset)/2) + 1) not like '%fetch%'
ORDER BY  total_elapsed_time / execution_count DESC;