SQL SERVER,查看耗时长，CPU 100% 的SQL

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])='PayLog'  
ORDER BY [cpu_time] DESC

'PayLog' 为数据库名

1、查看当前的数据库用户连接数

USE master

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

SELECT COUNT(*) FROM [sys].[dm_exec_sessions] WHERE [session_id]>50

2、查CPU使用率前10 的SQL语句（这个SQL好用）：

三表查询：

SELECT TOP 10

        st.text AS SQL_Full                                        --父级完整语句

        ,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) as SQL_Part    --统计对应的部分语句

        , CAST( ((qs.total_elapsed_time / 1000000.0)/qs.execution_count) AS DECIMAL(28,2) ) AS [平均消耗秒数]

        , CAST(qs.last_elapsed_time / 1000000.0 AS DECIMAL(28, 2)) AS [最后完成消耗秒数]

        , qs.last_execution_time AS [最后执行时间]

        , CAST(qs.min_elapsed_time / 1000000.0 AS DECIMAL(28, 2)) AS [最小消耗秒数]

        , CAST(qs.max_elapsed_time / 1000000.0 AS DECIMAL(28, 2)) AS [最大消耗秒数]

        , CAST(qs.total_elapsed_time / 1000000.0 AS DECIMAL(28, 2)) AS [总消耗秒数]

        , (qs.execution_count) AS [总执行次数]

        , creation_time AS [编译计划的时间]

        , CAST(qs.last_worker_time / 1000000.0 AS DECIMAL(28, 2)) AS [最后完成占用CPU秒数]

        , qp.query_plan

    from sys.dm_exec_query_stats qs

        CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) AS st

        CROSS APPLY sys.dm_exec_query_plan(qs.plan_handle) qp

WHERE qs.last_execution_time>DATEADD(n,-30,GETDATE())

ORDER BY qs.last_worker_time DESC

3、查阻塞：

SELECT R.session_id AS BlockedSessionID ,
S.session_id AS BlockingSessionID ,
Q1.text AS BlockedSession_TSQL ,
Q2.text AS BlockingSession_TSQL ,
C1.most_recent_sql_handle AS BlockedSession_SQLHandle ,
C2.most_recent_sql_handle AS BlockingSession_SQLHandle ,
S.original_login_name AS BlockingSession_LoginName ,
S.program_name AS BlockingSession_ApplicationName ,
S.host_name AS BlockingSession_HostName
FROM sys.dm_exec_requests AS R
INNER JOIN sys.dm_exec_sessions AS S ON R.blocking_session_id = S.session_id
INNER JOIN sys.dm_exec_connections AS C1 ON R.session_id = C1.most_recent_session_id
INNER JOIN sys.dm_exec_connections AS C2 ON S.session_id = C2.most_recent_session_id
CROSS APPLY sys.dm_exec_sql_text(C1.most_recent_sql_handle) AS Q1
CROSS APPLY sys.dm_exec_sql_text(C2.most_recent_sql_handle) AS Q2