|
[php]
14:13:01 SQL> select * from temp_trial_3006;
9651547 rows selected.
Elapsed: 00:01:42.29
Statistics
----------------------------------------------------------
0 recursive calls
0 db block gets
665940 consistent gets
0 physical reads
936 redo size
253514499 bytes sent via SQL*Net to client
7078451 bytes received via SQL*Net from client
643438 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
9651547 rows processed
14:14:54 SQL> 14:14:54 SQL> r
1* select * from temp_trial_3006
9651547 rows selected.
Elapsed: 00:01:42.93
Statistics
----------------------------------------------------------
0 recursive calls
0 db block gets
665940 consistent gets
0 physical reads
936 redo size
253514499 bytes sent via SQL*Net to client
7078451 bytes received via SQL*Net from client
643438 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
9651547 rows processed
14:17:19 SQL> select * from temp_trial_3006_iot;
9651547 rows selected.
Elapsed: 00:01:42.48
Statistics
----------------------------------------------------------
0 recursive calls
0 db block gets
663793 consistent gets
0 physical reads
0 redo size
253514499 bytes sent via SQL*Net to client
7078451 bytes received via SQL*Net from client
643438 SQL*Net roundtrips to/from client
0 sorts (memory)
0 sorts (disk)
9651547 rows processed
14:29:36 SQL>
数据环境
SQL> select segment_name,blocks from dba_segments where owner='YXY';
SEGMENT_NAME BLOCKS
------------------------------ ----------
TEMP_TRIAL_3006 24320
SYS_IOT_TOP_21509 22016
SQL> show parameter cache;
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_cache_size big integer 3992977408
在上面的测试过程中,有两个地方不太理解,请指点
1.为什么 select * from temp_trial_3006 在第二次执行还会产生 936 redo size ?
2.为什么 select * from temp_trial_3006_iot 查询这个IOT表不会产生REDO ?
————————————————————————————————
[/php] |
|