SQL Server查找哪些执行慢的语句

1、根据 https://learn.microsoft.com/zh-cn/troubleshoot/sql/database-engine/performance/troubleshoot-slow-running-queries网址提供的脚本。

SELECT 
    req.session_id
    , req.total_elapsed_time AS duration_ms
    , req.cpu_time AS cpu_time_ms
    , req.total_elapsed_time - req.cpu_time AS wait_time
    , req.logical_reads
    , SUBSTRING (REPLACE (REPLACE (SUBSTRING (ST.text, (req.statement_start_offset/2) + 1, 
       ((CASE statement_end_offset
           WHEN -1
           THEN DATALENGTH(ST.text)  
           ELSE req.statement_end_offset
         END - req.statement_start_offset)/2) + 1) , CHAR(10), ' '), CHAR(13), ' '), 
      1, 512)  AS statement_text  
FROM sys.dm_exec_requests AS req
    CROSS APPLY sys.dm_exec_sql_text(req.sql_handle) AS ST
ORDER BY total_elapsed_time DESC;

 执行效果如下图所示。

2、若想查看更详细的信息，可执行以下语句。

SELECT top 20  
    (total_elapsed_time / execution_count)/1000 N'平均时间ms'  
    ,total_elapsed_time/1000 N'总花费时间ms'  
    ,total_worker_time/1000 N'所用的CPU总时间ms'  
    ,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'  
    ,creation_time N'语句编译时间'  
    ,last_execution_time N'上次执行时间'  
    ,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'  
    ,qp.query_plan  
FROM  sys.dm_exec_query_stats AS qs
CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) st
CROSS APPLY sys.dm_exec_query_plan(qs.plan_handle) qp  
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; 

 执行效果如下图所示：