dbcc freeProcCache

 

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;

 

SELECT TOP 2000 
       ST.text AS '执行的SQL语句',
       QS.execution_count AS '执行次数',
       QS.total_elapsed_time AS '耗时',
       QS.total_logical_reads AS '逻辑读取次数',
       QS.total_logical_writes AS '逻辑写入次数',
       QS.total_physical_reads AS '物理读取次数',       
       QS.creation_time AS '执行时间' ,  
       QS.*
FROM   sys.dm_exec_query_stats QS
       CROSS APPLY 
sys.dm_exec_sql_text(QS.sql_handle) ST
WHERE  QS.creation_time BETWEEN '2020-06-11 00:00:00' AND '2020-06-12 00:00:00' 
ORDER BY
     QS.total_elapsed_time DESC

使用以上语句的意义在于找到那些语句被执行的次数比较频繁，进而优化接口，然后找出那些sql语句执行时间长，进而做性能分析，加入查询索引等