sqlserver常用调优脚本

------------------------最耗时的sql---------------------------------------
DECLARE @n INT; 
SET @n = 500;

WITH    cte1
          AS ( SELECT   a.* ,
                        t.*
               FROM     sys.dm_exec_query_stats a
                        CROSS APPLY sys.dm_exec_sql_text(a.plan_handle) t
               WHERE    t.dbid >= 5
             )
    SELECT  t.dbid ,
            DB_NAME(t.dbid) AS dbname ,
            a.total_worker_time ,
            a.avg_time_ms ,
            a.execution_count ,
            a.cache_count ,
            REPLACE(REPLACE(t.text, CHAR(10), ' '), CHAR(13), ' ')
    FROM    ( SELECT TOP ( @n )
                        plan_handle ,
                        SUM(total_worker_time) / 1000 AS total_worker_time ,
                        SUM(execution_count) AS execution_count ,
                        COUNT(1) AS cache_count ,
                        ( SUM(total_worker_time) / SUM(execution_count) )
                        / 1000 AS avg_time_ms
              FROM      cte1
              GROUP BY  plan_handle
              ORDER BY  avg_time_ms DESC
            ) a
            CROSS APPLY sys.dm_exec_sql_text(a.plan_handle) t
    WHERE   avg_time_ms > 200
    ORDER BY avg_time_ms DESC;

GO


------------------------最频繁的sql---------------------------------------
DECLARE @n INT; 
SET @n = 500;
WITH    cte1
          AS ( SELECT   a.* ,
                        t.*
               FROM     sys.dm_exec_query_stats a
                        CROSS APPLY sys.dm_exec_sql_text(a.plan_handle) t
               WHERE    t.dbid >= 5
             )
    SELECT  t.dbid ,
            DB_NAME(t.dbid) AS dbname ,
            a.execution_count ,
            a.total_worker_time ,
            a.avg_time_ms ,
            a.cache_count ,
            REPLACE(REPLACE(t.text, CHAR(10), ' '), CHAR(13), ' ')
    FROM    ( SELECT TOP ( @n )
                        plan_handle ,
                        SUM(total_worker_time) / 1000 AS total_worker_time ,
                        SUM(execution_count) AS execution_count ,
                        COUNT(1) AS cache_count ,
                        ( SUM(total_worker_time) / SUM(execution_count) )
                        / 1000 AS avg_time_ms
              FROM      cte1
              GROUP BY  plan_handle
              ORDER BY  avg_time_ms DESC
            ) a
            CROSS APPLY sys.dm_exec_sql_text(a.plan_handle) t
    ORDER BY execution_count DESC;
GO



------------------------耗cpu的sql---------------------------------------
DECLARE @n INT; 
SET @n = 500;
WITH    cte1
          AS ( SELECT   a.* ,
                        t.*
               FROM     sys.dm_exec_query_stats a
                        CROSS APPLY sys.dm_exec_sql_text(a.plan_handle) t
               WHERE    t.dbid >= 5
             )
    SELECT  t.dbid ,
            DB_NAME(t.dbid) AS dbname ,
            a.total_logical_reads ,
            a.avg_reads ,
            a.total_logical_writes ,
            a.avg_writes ,
            a.execution_count ,
            a.total_worker_time ,
            a.avg_time_ms ,
            a.cache_count ,
            REPLACE(REPLACE(t.text, CHAR(10), ' '), CHAR(13), ' ')
    FROM    ( SELECT TOP ( @n )
                        plan_handle ,
                        SUM(total_logical_reads) AS total_logical_reads ,
                        ( SUM(total_logical_reads) / SUM(execution_count) ) AS avg_reads ,
                        SUM(total_logical_writes) AS total_logical_writes ,
                        ( SUM(total_logical_writes) / SUM(execution_count) ) AS avg_writes ,
                        SUM(execution_count) AS execution_count ,
                        COUNT(1) AS cache_count ,
                        SUM(total_worker_time) AS total_worker_time ,
                        ( SUM(total_worker_time) / SUM(execution_count) )
                        / 1000 AS avg_time_ms
              FROM      cte1
              GROUP BY  plan_handle
              ORDER BY  ( ( SUM(total_logical_reads) / SUM(execution_count) )
                          + ( SUM(total_logical_writes) / SUM(execution_count) ) ) DESC
            ) a
            CROSS APPLY sys.dm_exec_sql_text(a.plan_handle) t
    ORDER BY ( avg_reads + avg_writes ) DESC;
GO


-----------------------当前数据库可能缺少的索引-------------------------------
SELECT  d.* ,
        s.avg_total_user_cost ,
        s.avg_user_impact ,
        s.last_user_seek ,
        s.unique_compiles
FROM    sys.dm_db_missing_index_group_stats s ,
        sys.dm_db_missing_index_groups g ,
        sys.dm_db_missing_index_details d
WHERE   s.group_handle = g.index_group_handle
        AND d.index_handle = g.index_handle
ORDER BY s.avg_user_impact DESC;


-----------------------当前数据库没用到的索引-------------------------------
SELECT  tb_name = OBJECT_NAME(a.object_id) ,
        idx_name = b.name ,
        last_user_update ,
        c.colid ,
        c.keyno ,
        col_name = d.name
INTO    #tmp
FROM    sys.dm_db_index_usage_stats a
        LEFT JOIN sys.indexes b ON a.object_id = b.object_id
                                   AND a.index_id = b.index_id
        LEFT JOIN sys.sysindexkeys c ON c.id = a.object_id
                                        AND c.indid = a.index_id
        LEFT JOIN syscolumns d ON d.id = c.id
                                  AND d.colid = c.colid
WHERE   database_id = DB_ID()
        AND last_user_seek IS NULL
        AND last_user_scan IS NULL
        AND last_user_lookup IS NULL
        AND last_user_update IS NOT NULL
ORDER BY tb_name ,
        idx_name ,
        keyno;
SELECT  tb_name ,
        idx_name ,
        last_user_update ,
        keywords = STUFF(( SELECT   ',' + col_name
                           FROM     #tmp
                           WHERE    tb_name = a.tb_name
                                    AND idx_name = a.idx_name
                           ORDER BY tb_name ,
                                    idx_name ,
                                    keyno
                         FOR
                           XML PATH('')
                         ), 1, 1, '')
FROM    #tmp a
GROUP BY tb_name ,
        idx_name ,
        last_user_update;
DROP TABLE #tmp;
GO

------------------------------当前数据库索引的使用率--------------
SELECT  OBJECT_NAME(object_id) AS table_name ,
        ( SELECT    name
          FROM      sys.indexes
          WHERE     object_id = stats.object_id
                    AND index_id = stats.index_id
        ) AS index_name ,
        *
FROM    sys.dm_db_index_usage_stats AS stats
WHERE   database_id = DB_ID()
ORDER BY table_name;

 
--当前数据库指定表的索引使用情况
DECLARE @table AS NVARCHAR(100);
SET @table = 't_ire_candidate';

SELECT  ( SELECT    name
          FROM      sys.indexes
          WHERE     object_id = stats.object_id
                    AND index_id = stats.index_id
        ) AS index_name ,
        *
FROM    sys.dm_db_index_usage_stats AS stats
WHERE   object_id = OBJECT_ID(@table)
ORDER BY user_seeks ,
        user_scans ,
        user_lookups ASC;
GO

-- 查找阻塞，通过 a.blocking_session_id 查看引起阻塞的进程，text是对应的sql脚本
SELECT  b.text , -- sql执行计划
        b.dbid ,
        DB_NAME(b.dbid) AS dbname ,
        a.session_id , -- 执行会话id
        a.blocking_session_id , -- 引起阻塞的会话id
        a.status ,
        a.command ,
        a.wait_time ,
        a.wait_type ,
        a.wait_resource ,
        a.total_elapsed_time
FROM    sys.dm_exec_requests a
        CROSS APPLY sys.dm_exec_sql_text(a.sql_handle) b
WHERE   session_id IN ( SELECT DISTINCT
                                request_session_id
                        FROM    sys.dm_tran_locks );

 摘录http://www.cnblogs.com/chengxiaohui/articles/6377569.html