[20160701]调整AWR快照生成时间.txt

--itpub有人要求调整AWR快照生成时间,也就是要求不是整点执行,实际上11g有1个参数awr_snapshot_time_offset可以控制这种引为.
--测试看看:
--链接:http://www.itpub.net/thread-1622837-1-1.html

1.环境:
SYS@book> @ &r/ver1
PORT_STRING                    VERSION        BANNER
------------------------------ -------------- --------------------------------------------------------------------------------
x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production

SYS@book> alter system set awr_snapshot_time_offset=900 scope=memory;
System altered.

2.等下午观察:

SELECT *
  FROM (SELECT snap_id
                ,snap_level
                ,instance_number
                ,TO_CHAR (begin_interval_time, 'yyyy/mm/dd hh24:mi:ss')
                    begin_interval_time
                ,TO_CHAR (end_interval_time, 'yyyy/mm/dd hh24:mi:ss')
                    end_interval_time
                ,TO_CHAR (flush_elapsed) flush_elapsed
                ,TO_CHAR (startup_time, 'yyyy/mm/dd hh24:mi:ss') startup_time
                ,error_count
            FROM DBA_HIST_SNAPSHOT
           WHERE dbid = 0.133740171e+010
        ORDER BY 1 DESC)
WHERE ROWNUM <= 5;

   SNAP_ID SNAP_LEVEL INSTANCE_NUMBER BEGIN_INTERVAL_TIME END_INTERVAL_TIME   FLUSH_ELAPSED      STARTUP_TIME        ERROR_COUNT
---------- ---------- --------------- ------------------- ------------------- ------------------ ------------------- -----------
      4189          1               1 2016/07/01 13:15:39 2016/07/01 14:15:40 +00000 00:00:00.1  2016/06/30 11:58:01           0
      4188          1               1 2016/07/01 12:15:37 2016/07/01 13:15:39 +00000 00:00:00.6  2016/06/30 11:58:01           0
      4187          1               1 2016/07/01 11:15:36 2016/07/01 12:15:37 +00000 00:00:00.1  2016/06/30 11:58:01           0
      4186          1               1 2016/07/01 10:00:34 2016/07/01 11:15:36 +00000 00:00:00.7  2016/06/30 11:58:01           0
      4185          1               1 2016/07/01 09:00:32 2016/07/01 10:00:34 +00000 00:00:00.6  2016/06/30 11:58:01           0

--从11:15开始,以后生成的都是15分钟的.