今天有客户报启动数据库遇到如下问题：
ORA-16038: log 3 sequence# 1126 cannot be archived
ORA-19809: limit exceeded for recovery files
ORA-00312: online log 3 thread 1: '/opt/oracle/product/10.1/oradata/orcl/redo03.log'
查了一下错误信息
ORA-19809: limit exceeded for recovery files
Cause: The limit for recovery files specified by the DB_RECOVERY_FILE_DEST_SIZE was exceeded.
Action: The error is accompanied by 19804. See message 19804 for further details.
ORA-19804: cannot reclaim string bytes disk space from string limit
Cause: Oracle cannot reclaim disk space of specified bytes from the DB_RECOVERY_FILE_DEST_SIZE limit.
Action: There are five possible solutions:
1) Take frequent backup of recovery area using RMAN.
2) Consider changing RMAN retention policy.
3) Consider changing RMAN archivelog deletion policy.
4) Add disk space and increase DB_RECOVERY_FILE_DEST_SIZE.
5) Delete files from recovery area using RMAN.
oracle10g在默认情况下，归档日志是保存在闪回恢复区的，如果你建库的时候用的默认设置，
闪回恢复区应该是2G，空间被占满了以后就无法再归档了
SQL> show parameter db_recovery_file
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
db_recovery_file_dest string D:/oracle/product/10.2.0/flash
_recovery_area
db_recovery_file_dest_size big integer 2G
执行下面的语句，可以看到闪回恢复区的使用情况
select reason,object_type,suggested_action from dba_outstanding_alerts; ——我在我电脑里试了，但是如果是没有打开的时候是不允许查询的，打开后我查询，没有数据。
解决方法：
1.将归档设置到其他目录，修改alter system set log_archive_dest = 其他路径
2.转移或者删除闪回恢复区里的归档日志。
3.增大闪回恢复区。
ALTER SYSTEM SET db_recovery_file_dest_size=4g scope=both ; ——这个方法是比较管用的，一下就搞定了、