一般我们可以使用sql server自带的性能分析追踪工具sql profiler分析数据库设计所产生问题的来源，进行有针对性的处理。但我们也可以通过自己写SQL语句来有针对性的进行性能方面的查询。通常会用到如下三个系统视图：sys.sysprocesses ,dm_exec_sessions ,dm_exec_requests --一、查看当前的数据库用户连接有多少 USE master GO SELECT* FROMsys.[sysprocesses] WHERE [spid] > 50 --AND DB_NAME([dbid])='gposdb' SELECTCOUNT(*) FROM[sys].[dm_exec_sessions] WHERE [session_id] > 50 --二、选取前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' FROMsys.[dm_exec_requests] AS der CROSS APPLY sys.[dm_exec_sql_text](der.[sql_handle]) AS dest WHERE [session_id] > 50 AND DB_NAME(der.[database_id]) = 'gposdb' ORDER BY [cpu_time] DESC --三、查询前10个最耗CPU时间的SQL语句 SELECT TOP 10 dest.[text] AS 'sql语句' FROMsys.[dm_exec_requests] AS der CROSS APPLY sys.[dm_exec_sql_text](der.[sql_handle]) AS dest WHERE [session_id] > 50 ORDER BY [cpu_time] DESC --四、查询会话中有多少个worker在等待 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' , der.[wait_type] AS '等待资源类型' , [wait_time] AS '等待时间' , [wait_resource] AS '等待的资源' , [dows].[waiting_tasks_count] AS '当前正在进行等待的任务数' , [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' FROMsys.[dm_exec_requests] AS der INNER JOIN [sys].[dm_os_wait_stats] AS dows ON der.[wait_type] = [dows].[wait_type] CROSS APPLY sys.[dm_exec_sql_text](der.[sql_handle]) AS dest WHERE [session_id] > 50 ORDER BY [cpu_time] DESC --五、查询CPU占用高的语句 SELECT TOP 10 total_worker_time / execution_count AS avg_cpu_cost , plan_handle , execution_count , ( SELECTSUBSTRING(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) FROMsys.dm_exec_sql_text(sql_handle) ) AS query_text FROMsys.dm_exec_query_stats ORDER BY [avg_cpu_cost] DESC
