--************模拟使用index不能提高效率的情况
Insert Into t1 Select * From t1           --构建大表，百万数据以上   
Select Count(*) From t1                   --1265792
Alter Table t1 Move                       --整理表的存储
Select Min(object_id) From t1      --object_id 最小=2  有128个
Update t1 Set object_id = 9000 Where object_id > 2   --卡住不动了
Select * From v$flash_recovery_area_usage  --查看归档日志的表空气使用情况 ARCHIVELOG 98.5%
Select * From v$session_wait Where wait_class <> 'Idle'             --查看等待的情况
show parameter db_recovery                 --查看db_recovery_file_dest_size属性值 2G
Alter System Set db_recovery_file_dest_size=5G       --属性值改为5G
/*
Select * From v$streams_transaction           --stream流,用于多实例互相同步
golden gate 可以实现oracle到异构数据库的同步
*/
Select object_id,Count(*) From t1 Group By object_id                       --
--执行计划
-----------------------------------------------------------------------------------
| Id  | Operation          | Name | Rows  | Bytes |TempSpc| Cost (%CPU)| Time     |
-----------------------------------------------------------------------------------
|   0 | SELECT STATEMENT   |      |  9889 | 49445 |       |   327   (2)| 00:00:04 |
|   1 |  HASH GROUP BY     |      |  9889 | 49445 |  1064K|   327   (2)| 00:00:04 |
|   2 |   TABLE ACCESS FULL| T1   | 79112 |   386K|       |   218   (1)| 00:00:03 |
-----------------------------------------------------------------------------------




统计信息
----------------------------------------------------------
          1  recursive calls
          0  db block gets
      15798  consistent gets
       9545  physical reads
          0  redo size
        516  bytes sent via SQL*Net to client
        385  bytes received via SQL*Net from client
          2  SQL*Net roundtrips to/from client
          0  sorts (memory)
          0  sorts (disk)
          2  rows processed


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select * from v$session_longops --CPU运行超过6秒的动作