该篇文章模拟用户活动事物上的UNDO块损坏恢复
数据库版本
SQL> select * from gv$version;
INST_ID BANNER
---------- --------------------------------------------------------------------------------
1 Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 - 64bit Production
1 PL/SQL Release 11.2.0.3.0 - Production
1 CORE 11.2.0.3.0 ...
