SQL性能优化常用语句（摘录网上）

SELECT IDENTITY(BIGINT, 1, 1) AS RowNumber,* 
into TableName
FROM fn_trace_gettable(‘trace.trc‘, default)

SELECT top 100
    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,creation_time
 FROM sys.dm_exec_query_stats
 where creation_time > ‘2014-11-01‘
and (total_worker_time/execution_count) > 146341
ORDER BY [avg_cpu_cost] DESC

SELECT a.* FROM sys.[sysprocesses] a
WHERE a.[spid]>50 AND DB_NAME(a.[dbid])=‘DBName‘ and a.spid <> @@SPID and a.blocked > 0

SELECT COUNT(*) FROM [sys].[dm_exec_sessions] WHERE [session_id]>50