https://learn.microsoft.com/zh-cn/troubleshoot/sql/database-engine/performance/troubleshoot-slow-running-queries

１SqlIO优化

set statistics io on
--sql
set statistics io off

２Sql占用CPU时间

select

    c.total_worker_time, c.last_execution_time,c.execution_count,c.total_logical_reads,c.total_logical_writes,c.total_elapsed_time,c.last_elapsed_time,

    q.[text]

from

    (select top 50 qs.*

    from sys.dm_exec_query_stats qs

    order by qs.total_worker_time desc) as c

    cross apply sys.dm_exec_sql_text(plan_handle) as q

order by c.total_worker_time desc

go

3查正在执行的SQL 

SELECT deqs.last_execution_time AS [Time], dest.TEXT AS [Query]

FROM sys.dm_exec_query_stats AS deqs CROSS APPLY sys.dm_exec_sql_text(deqs.sql_handle) AS dest ORDER BY deqs.last_execution_time DESC

　　2　

SELECT [Spid] = session_Id

, ecid

, [Database] = DB_NAME(sp.dbid)

, [User] = nt_username

, [Status] = er.status

, [Wait] = wait_type

, [Individual Query] = SUBSTRING (qt.text,

er.statement_start_offset/2,

(CASE WHEN er.statement_end_offset = -1

THEN LEN(CONVERT(NVARCHAR(MAX), qt.text)) * 2

ELSE er.statement_end_offset END -

er.statement_start_offset)/2)

,[Parent Query] = qt.text

, Program = program_name

, Hostname

, nt_domain

, start_time

FROM sys.dm_exec_requests er

INNER JOIN sys.sysprocesses sp ON er.session_id = sp.spid

CROSS APPLY sys.dm_exec_sql_text(er.sql_handle)as qt

WHERE session_Id > 50 -- Ignore system spids.

AND session_Id NOT IN (@@SPID) -- Ignore this current statement.

ORDER BY 1, 2