查询CPU占用高的SQL语句的解决方案

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;下面小编收集了SQL Server中如何查询CPU占用高的SQL语句,希望大大家能有所帮助。

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

1、查看当前的数据库用户连接数

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

2、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

3、查询前10个最耗CPU时间的SQL语句

–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

4、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

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    原文作者:小明yz
    原文地址: https://www.jianshu.com/p/067237c07098
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