oracle中truncate、drop等ddl语句都产生redo 和undo信息
sys@ORCL> select m.value,s.name from v$mystat m join v$statname s on m.statistic#=s.statistic# where s.name in ('undo change vector size', 'redo size');
VALUE NAME
---------- ----------------------------------------------------------------
0 redo size
0 undo change vector size
sys@ORCL> truncate table hn.emp;
Table truncated.
sys@ORCL> select * from hn.emp;
no rows selected
sys@ORCL> select m.value,s.name from v$mystat m join v$statname s on m.statistic#=s.statistic# where s.name in ('undo change vector size', 'redo size');
VALUE NAME
---------- ----------------------------------------------------------------
7028 redo size
2108 undo change vector size
sys@ORCL>
证明：truncate产生redo和undo信息
sys@ORCL> select m.value,s.name from v$mystat m join v$statname s on m.statistic#=s.statistic# where s.name in ('undo change vector size', 'redo size');
VALUE NAME
---------- ----------------------------------------------------------------
7028 redo size
2108 undo change vector size
sys@ORCL> drop table hn.emp;
Table dropped.
sys@ORCL> select m.value,s.name from v$mystat m join v$statname s on m.statistic#=s.statistic# where s.name in ('undo change vector size', 'redo size');
VALUE NAME
---------- ----------------------------------------------------------------
14080 redo size
4172 undo change vector size
证明：drop语句也产生redo和undo信息
阅读(2112) | 评论(0) | 转发(0) |
