MSSQL性能优化之sqlserver常用资源消耗sql
--当前的数据库用户连接情况--
SELECT * FROM sys.[sysprocesses] WHERE [spid]>50 AND DB_NAME([dbid])='db_name'SELECT * FROM [sys].[dm_exec_sessions] WHERE [session_id]>50
---选取了前10个最耗CPU时间的会话---
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 derCROSS APPLYsys.[dm_exec_sql_text](der.[sql_handle]) AS destWHERE [session_id]>50 AND DB_NAME(der.[database_id])='db_name'ORDER BY [cpu_time] DESC
---选取了前10个最耗CPU时间的SQL---
SELECT TOP 10dest.[text] AS 'sql语句'FROM sys.[dm_exec_requests] AS derCROSS APPLYsys.[dm_exec_sql_text](der.[sql_handle]) AS destWHERE [session_id]>50ORDER BY [cpu_time] DESC
SELECT TOP 10total_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 = -1THEN LEN(CONVERT(nvarchar(max), text)) * 2ELSE statement_end_offsetEND - statement_start_offset)/2)FROM sys.dm_exec_sql_text(sql_handle)) AS query_textFROM sys.dm_exec_query_statsORDER BY [avg_cpu_cost] DESC
----查询缺失索引----
SELECTDatabaseName = DB_NAME(database_id),[Number Indexes Missing] = count(*)FROM sys.dm_db_missing_index_detailsGROUP BY DB_NAME(database_id)ORDER BY 2 DESC;
SELECT TOP 10[Total Cost] = ROUND(avg_total_user_cost * avg_user_impact * (user_seeks + user_scans),0), avg_user_impact, TableName = statement, [EqualityUsage] = equality_columns, [InequalityUsage] = inequality_columns, [Include Cloumns] = included_columnsFROM sys.dm_db_missing_index_groups gINNER JOIN sys.dm_db_missing_index_group_stats sON s.group_handle = g.index_group_handleINNER JOIN sys.dm_db_missing_index_details dON d.index_handle = g.index_handleORDER BY [Total Cost] DESC;
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