ORA-16038，ORA-19809，ORA-00312问题解决

启动数据库出现如下错误：

SQL> startup
ORACLE instance started.

Total System Global Area 599785472 bytes
Fixed Size 1250356 bytes
Variable Size 209718220 bytes
Database Buffers 381681664 bytes
Redo Buffers 7135232 bytes
Database mounted.
ORA-16038: log 3 sequence# 235 cannot be archived
ORA-19809: limit exceeded for recovery files
ORA-00312: online log 3 thread 1:
'D:/ORACLE/PRODUCT/10.2.0/ORADATA/MYDB/REDO03.LOG'

在线日志无法归档，由于在线日志出错（可能由不正常数据库关闭或错误sql造成），可以通过clear在线日志进行解决

SQL> edit
Wrote file afiedt.buf

1* alter database clear unarchived logfile 'D:/ORACLE/PRODUCT/10.2.0/ORADATA/MYDB/REDO03.LOG'
SQL> /

Database altered.

然后关闭数据库，重新启动，数据库启动正常

SQL> shutdown immediate
ORA-01109: database not open

Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.

Total System Global Area 599785472 bytes
Fixed Size 1250356 bytes
Variable Size 209718220 bytes
Database Buffers 381681664 bytes
Redo Buffers 7135232 bytes
Database mounted.
Database opened.

当不能clear时（非current），可以使用alter database drop logfile group xxxx.

group number 可以从v$logfile中查看