这里不是说了么 The first set opens -- the database with the NORESETLOGS option and should be used only if -- the current versions of all online logs are available. The second -- set opens the database with the RESETLOGS option and should be used -- if online logs are unavailable.第一种,以noresetlogs方式打开,是在所有的在线日志可用的情况下,否则(redo日志出现了损坏)要以resetlogs的方式打开具体的官方解释: RESETLOGS resets the current log sequence number to 1 and invalidates all redo entries in the online and archived redo log files. You must use this option to open the database after performing media recovery with a backup controlfile. After opening the database with this option you should perform. a complete database backup.NORESETLOGS leaves the log sequence number and redo log files in their current state.即,如果使用resetlogs的方式,会截断日志,将当前的日志序列重置为1,并使所有原来的在线和归档日志失效。
The first set opens
-- the database with the NORESETLOGS option and should be used only if
-- the current versions of all online logs are available. The second
-- set opens the database with the RESETLOGS option and should be used
-- if online logs are unavailable.第一种,以noresetlogs方式打开,是在所有的在线日志可用的情况下,否则(redo日志出现了损坏)要以resetlogs的方式打开具体的官方解释:
RESETLOGS
resets the current log sequence number to 1 and invalidates all redo entries in the online and archived redo log files. You must use this option to open the database after performing media recovery with a backup controlfile. After opening the
database with this option you should perform. a complete database backup.NORESETLOGS
leaves the log sequence number and redo log files in their current state.即,如果使用resetlogs的方式,会截断日志,将当前的日志序列重置为1,并使所有原来的在线和归档日志失效。
如果一致,则不会丢失数据
但是并不推荐
注意备份
resetlogs 是将日志组清空,重新开始日志计数。 这个时候 以前做过的备份 就无效了,需要重新做备份。 noresetlogs创建了控制文件也没关系, 等到你alter database open 提示无法打开,需要用resetlog的时候 再执行
alter database open resetlogs;就行了