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SQL Server中查询CPU占用高的SQL语句

SQL Server 作者:taogchan 时间:2014-12-03 14:58:57 0 删除 编辑
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 master

GO

SELECT * 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

 

 
SQL 代码   复制
 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

 

 
SQL 代码   复制
 --在SSMS里选择以文本格式显示结果  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 

 

 
SQL 代码   复制
 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

 

 
SQL 代码   复制
 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_text    FROM sys.dm_exec_query_stats    ORDER BY [avg_cpu_cost] DESC 

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