SQL Server中查询CPU占用高的SQL语句

本文导读：触发器造成死锁、作业多且频繁、中间表的大量使用、游标的大量使用、索引的设计不合理、事务操作频繁、SQL语句设计不合理，都会造成查询效率低下、影响服务器性能的发挥。我们可以使用sql server自带的性能分析追踪工具sql profiler分析数据库设计所产生问题的来源，进行有针对性的处理；下面介绍SQL Server中如何查询CPU占用高的SQL语句

SQL Server中查询CPU占用高的情况，会用到sys.sysprocesses ,dm_exec_sessions ,dm_exec_requests

 

一、查看当前的数据库用户连接有多少

USE masterGOSELECT * FROM sys.[sysprocesses] WHERE [spid]>50 --AND DB_NAME([dbid])='gposdb'SELECT COUNT(*) FROM [sys].[dm_exec_sessions] WHERE [session_id]>50

二、选取前10个最耗CPU时间的会话

SELECT TOP 10[session_id],[request_id],[start_time] AS '开始时间',[status] AS '状态',[command] AS '命令',dest.[text] AS 'sql语句', DB_NAME([database_id]) AS '数据库名',[blocking_session_id] AS '正在阻塞其他会话的会话ID',[wait_type] AS '等待资源类型',[wait_time] AS '等待时间',[wait_resource] AS '等待的资源',[reads] AS '物理读次数',[writes] AS '写次数',[logical_reads] AS '逻辑读次数',[row_count] AS '返回结果行数'FROM sys.[dm_exec_requests] AS der CROSS APPLY sys.[dm_exec_sql_text](der.[sql_handle]) AS dest WHERE [session_id]>50 AND DB_NAME(der.[database_id])='gposdb'  ORDER BY [cpu_time] DESC

 

三、查询前10个最耗CPU时间的SQL语句

SELECT TOP 10 dest.[text] AS 'sql语句'FROM sys.[dm_exec_requests] AS der CROSS APPLY sys.[dm_exec_sql_text](der.[sql_handle]) AS dest WHERE [session_id]>50  ORDER BY [cpu_time] DESC

 

四、查询会话中有多少个worker在等待 

SELECT TOP 10 [session_id], [request_id], [start_time] AS '开始时间', [status] AS '状态', [command] AS '命令', dest.[text] AS 'sql语句',  DB_NAME([database_id]) AS '数据库名', [blocking_session_id] AS '正在阻塞其他会话的会话ID', der.[wait_type] AS '等待资源类型', [wait_time] AS '等待时间', [wait_resource] AS '等待的资源', [dows].[waiting_tasks_count] AS '当前正在进行等待的任务数', [reads] AS '物理读次数', [writes] AS '写次数', [logical_reads] AS '逻辑读次数', [row_count] AS '返回结果行数' FROM sys.[dm_exec_requests] AS der  INNER JOIN [sys].[dm_os_wait_stats] AS dows  ON der.[wait_type]=[dows].[wait_type] CROSS APPLY  sys.[dm_exec_sql_text](der.[sql_handle]) AS dest  WHERE [session_id]>50   ORDER BY [cpu_time] DESC

 

五、查询CPU占用高的语句

SELECT TOP 10   total_worker_time/execution_count AS avg_cpu_cost, plan_handle,   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_textFROM sys.dm_exec_query_statsORDER BY [avg_cpu_cost] DESC