Sql Server CPU 性能排查及优化的相关 Sql

Sql Server CPU 性能排查及优化的相关 Sql 语句，非常好的SQL语句，记录于此：

--Begin Cpu 分析优化的相关 Sql 

--使用DMV来分析SQL Server启动以来累计使用CPU资源最多的语句。例如下面的语句就可以列出前50名。select     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 qorder by c.total_worker_time descgo

-- 返回最经常运行的100条语句SELECT TOP 100 cp.cacheobjtype,cp.usecounts,cp.size_in_bytes,qs.statement_start_offset,qs.statement_end_offset,qt.dbid    ,qt.objectid                        ,SUBSTRING(qt.text,qs.statement_start_offset/2,                         (case when qs.statement_end_offset = -1                         then len(convert(nvarchar(max), qt.text)) * 2                         else qs.statement_end_offset end -qs.statement_start_offset)/2)     as statement FROM sys.dm_exec_query_stats qscross apply sys.dm_exec_sql_text(qs.sql_handle) as qtinner join sys.dm_exec_cached_plans as cp on qs.plan_handle=cp.plan_handlewhere cp.plan_handle=qs.plan_handleand cp.usecounts>4ORDER BY [dbid],[Usecounts] DESC

-- 返回做IO数目最多的50条语句以及它们的执行计划select top 50     (total_logical_reads/execution_count) as avg_logical_reads,    (total_logical_writes/execution_count) as avg_logical_writes,    (total_physical_reads/execution_count) as avg_phys_reads,     Execution_count,     statement_start_offset as stmt_start_offset, statement_end_offset as stmt_end_offset,substring(sql_text.text, (statement_start_offset/2), case when (statement_end_offset -statement_start_offset)/2 <=0 then 64000else (statement_end_offset -statement_start_offset)/2 end) as exec_statement,  sql_text.text,plan_text.*from sys.dm_exec_query_stats  cross apply sys.dm_exec_sql_text(sql_handle) as sql_textcross apply sys.dm_exec_query_plan(plan_handle) as plan_textorder by  (total_logical_reads + total_logical_writes) /Execution_count Desc

-- 计算signal wait占整wait时间的百分比-- 指令等待 CPU 资源的时间占总时间的百分比。如果超过 25% ，说明 CPU 紧张select convert(numeric(5,4),sum(signal_wait_time_ms)/sum(wait_time_ms)) from Sys.dm_os_wait_stats 

-- 计算'Cxpacket'占整wait时间的百分比-- Cxpacket:Sql Server 在处理一句代价很大的语句，要不就是没有合适的索引或筛选条件没能筛选足够的记录，使得语句要返回大量的结果，当 >5% 说明有问题declare @Cxpacket bigintdeclare @Sumwaits bigintselect @Cxpacket = wait_time_msfrom Sys.dm_os_wait_statswhere wait_type = 'Cxpacket'select @Sumwaits = sum(wait_time_ms)from Sys.dm_os_wait_statsselect convert(numeric(5,4),@Cxpacket/@Sumwaits)

-- 查询当前数据库上所有用户表格在Row lock上发生阻塞的频率declare @dbid intselect @dbid = db_id()Select dbid=database_id, objectname=object_name(s.object_id), indexname=i.name, i.index_id    --, partition_number, row_lock_count, row_lock_wait_count, [block %]=cast (100.0 * row_lock_wait_count / (1 + row_lock_count) as numeric(15,2)), row_lock_wait_in_ms, [avg row lock waits in ms]=cast (1.0 * row_lock_wait_in_ms / (1 + row_lock_wait_count) as numeric(15,2))from sys.dm_db_index_operational_stats (@dbid, NULL, NULL, NULL) s,     sys.indexes iwhere objectproperty(s.object_id,'IsUserTable') = 1and i.object_id = s.object_idand i.index_id = s.index_idorder by row_lock_wait_count desc

--End Cpu 分析优化的相关 Sql 

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