SQL> col action for a26;

SQL> 

SQL> select d.NAME,d.PLATFORM_NAME,

  2         to_char(r.action_time, 'yyyy-mm-dd hh24:mi:ss') as action_time,

  3         r.action||' ' ||'PSU :' || r.version || '.'||r.id as action,

  4         decode (r.version || '.'||r.id,'11.2.0.3.5','Y','N') as upgraded

  5    from dba_registry_history r, v$database d

  6   where r.action_time = (select max(action_time) from dba_registry_history) ;

NAME         PLATFORM_NAME            ACTION_TIME          ACTION                     UPG

------------ ------------------------ -------------------- -------------------------- ---

ORCL5        Linux x86 64-bit         2014-04-15 11:18:46  APPLY PSU :11.2.0.3.0      N

1 row selected.

所以总结下来，我们的步骤是分成两步，第一步是给软件打patch，然后再对数据库dbf文件对一些数据字典等的修改。第一步需要听库处理，第二步是open库后处理。回退也是先弄软件，再弄数据库。

看PSU的自述文档是最重要的。