数据库资源按需分配
https://www.cnblogs.com/i6first/p/4138365.html
https://blog.csdn.net/kk185800961/article/details/49947571
Sqlserver 中视图sys.dm_exec_query_stats (Transact-SQL)各列的含义: https://docs.microsoft.com/zh-cn/previous-versions/sql/sql-server-2012/ms189741(v=sql.110)
返回 SQL Server 2012 中缓存查询计划的聚合性能统计信息。 缓存计划中的每个查询语句在该视图中对应一行,并且行的生存期与计划本身相关联。 在从缓存删除计划时,也将从该视图中删除对应行。
查询最耗CPU的资源时间
https://blog.csdn.net/wjbaiverson/article/details/48859079
--执行最慢的SQL语句
SELECT
(total_elapsed_time / execution_count)/1000 N'平均时间ms'
,total_elapsed_time/1000 N'总花费时间ms'
,total_worker_time/1000 N'所用的CPU总时间ms'
,total_physical_reads N'物理读取总次数'
,total_logical_reads/execution_count N'每次逻辑读次数'
,total_logical_reads N'逻辑读取总次数'
,total_logical_writes N'逻辑写入总次数'
,execution_count N'执行次数'
,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) N'执行语句'
,creation_time N'语句编译时间'
,last_execution_time N'上次执行时间'
FROM
sys.dm_exec_query_stats AS qs CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) st
WHERE
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) not like '�tch%'
ORDER BY
total_elapsed_time / execution_count DESC;
--总耗CPU最多的前个SQL
SELECT TOP 20
total_worker_time/1000 AS [总消耗CPU 时间(ms)],execution_count [运行次数],
qs.total_worker_time/qs.execution_count/1000 AS [平均消耗CPU 时间(ms)],
last_execution_time AS [最后一次执行时间],max_worker_time /1000 AS [最大执行时间(ms)],
SUBSTRING(qt.text,qs.statement_start_offset/2+1,
(CASE WHEN qs.statement_end_offset = -1
THEN DATALENGTH(qt.text)
ELSE qs.statement_end_offset END -qs.statement_start_offset)/2 + 1)
AS [使用CPU的语法], qt.text [完整语法],
qt.dbid, dbname=db_name(qt.dbid),
qt.objectid,object_name(qt.objectid,qt.dbid) ObjectName
FROM sys.dm_exec_query_stats qs WITH(nolock)
CROSS apply sys.dm_exec_sql_text(qs.sql_handle) AS qt
WHERE execution_count>1
ORDER BY total_worker_time DESC
--平均耗CPU最多的前个SQL
SELECT TOP 20
total_worker_time/1000 AS [总消耗CPU 时间(ms)],execution_count [运行次数],
qs.total_worker_time/qs.execution_count/1000 AS [平均消耗CPU 时间(ms)],
last_execution_time AS [最后一次执行时间],min_worker_time /1000 AS [最小执行时间(ms)],
max_worker_time /1000 AS [最大执行时间(ms)],
SUBSTRING(qt.text,qs.statement_start_offset/2+1,
(CASE WHEN qs.statement_end_offset = -1
THEN DATALENGTH(qt.text)
ELSE qs.statement_end_offset END -qs.statement_start_offset)/2 + 1)
AS [使用CPU的语法], qt.text [完整语法],
qt.dbid, dbname=db_name(qt.dbid),
qt.objectid,object_name(qt.objectid,qt.dbid) ObjectName
FROM sys.dm_exec_query_stats qs WITH(nolock)
CROSS apply sys.dm_exec_sql_text(qs.sql_handle) AS qt
WHERE execution_count>1
ORDER BY (qs.total_worker_time/qs.execution_count/1000) DESC