sqlserver 性能查询CPU占用高的sql

发布时间：2020-12-12 13:29:42 所属栏目：MsSql教程来源：网络整理

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

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
?
??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_text ? ?FROM sys.dm_exec_query_stats ? ?ORDER BY [avg_cpu_cost] DESC?
http://blog.itpub.net/22392018/viewspace-1355206/
http://blog.csdn.net/yenange/article/details/9852755 ? dm_exec_Sessions ?dm_exec_Connections 表中的数据字段解释参考网址

（编辑：李大同）

【声明】本站内容均来自网络，其相关言论仅代表作者个人观点，不代表本站立场。若无意侵犯到您的权利，请及时与联系站长删除相关内容!