--检测CPU压力的一个方法是计算运行状态下的工作进程数量，
--通过执行如下的DMV查询可以得到这个信息
SELECT
COUNT
(
*
)
AS
workers_waiting_for_cpu,t2.scheduler_id
FROM sys.dm_os_workers AS t1, sys.dm_os_schedulers AS t2
WHERE t1.state = ' RUNNABLE ' AND
t1.scheduler_address = t2.scheduler_address AND
t2.scheduler_id < 255
GROUP BY t2.scheduler_id
FROM sys.dm_os_workers AS t1, sys.dm_os_schedulers AS t2
WHERE t1.state = ' RUNNABLE ' AND
t1.scheduler_address = t2.scheduler_address AND
t2.scheduler_id < 255
GROUP BY t2.scheduler_id
--也可以执行如下的查询得到工作进程在可运行状态下花费的时间
SELECT SUM(signal_wait_time_ms) FROM sys.dm_os_wait_stats
--下面是一个DMV查询，它可以用来找出每次执行中占用CPU最多的钱10为查询，
--也列出了SQL语句的查询计划及计划被执行的次数。如果一个查询大家虽高，
--但执行次数少，那也可以采纳。
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
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
--以上DMV只显示当前被缓存的查询合计统计信息
--为了找出工作负荷中运行最频繁的查询，就需要执行下面的DMV查询。
SELECT
TOP
10
total_worker_time ,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 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 execution_count
--SQL Server在优化查询计划上花费的时间可以用下面的DMV查询
SELECT
*
FROM
sys.dm_exec_query_optimizer_info
WHERE
counter
=
'
optimizations
'
UNION
SELECT * FROM sys.dm_exec_query_optimizer_info WHERE counter = ' elapsed time '
SELECT TOP 10 plan_generation_num ,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
WHERE plan_generation_num > 1
ORDER BY execution_count
UNION
SELECT * FROM sys.dm_exec_query_optimizer_info WHERE counter = ' elapsed time '
SELECT TOP 10 plan_generation_num ,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
WHERE plan_generation_num > 1
ORDER BY execution_count
--检查高速缓存内存
DBCC
memorystatus
本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/dz45693/archive/2010/01/27/5260697.aspx
