SQL> startup
ORACLE instance started.

Total System Global Area 2137886720 bytes
Fixed Size                  2215064 bytes
Variable Size            1358955368 bytes
Database Buffers          771751936 bytes
Redo Buffers                4964352 bytes
Database mounted.
0ORA-00600: internal error code, arguments:kcratr1_lastbwr], [,], [, []

在open阶段时出错,这个错误一般是断电造成的

可用以下方法解决
startup mount;
recover database;
alter database open;