One of the redo log members in your database is lost. You queried V$logfile for further details.
What would be the member's status?
A. LOST
B. INVALID
C. EXPIRED
D. DELETED
E. CORRUPT
F. UNKNOWN
G. OBSOLETE
Answer: B
实验
1.删除group 2中唯一的redo log，数据库无法启动，清除日志，数据库启动成功，这时无法查看到V$logfile
2.给group 2加入一个新的日志文件，ALTER SYSTEM SWITCH LOGFILE，删除新日志文件，重启，查看V$logfile，变为INVALID
alter database clear logfile group 2 之后又重新上线
V$LOGFILE
Status of the log member:
-
INVALID- File is inaccessible -
STALE- File's contents are incomplete -
DELETED- File is no longer used - null - File is in use