在CLEAR操作后，OS会创建相应的日志组成员文件，然后数据库就可以正常读取了，此时并不需要通过restore和recover对数据库进行恢复和还原即可
测试2：正常关库后，删除在线日志文件
ZLM@ora10g> select group#,thread#,status,archived from v$log;
GROUP# THREAD# STATUS ARC
---------- ---------- ---------------- ---
1 1 CURRENT NO
2 1 INACTIVE YES
3 1 UNUSED YES
ZLM@ora10g> insert into t1 select * from dba_objects where rownum<11;
10 rows created.
ZLM@ora10g> select count(*) from t1;
COUNT(*)
----------
20
ZLM@ora10g> alter system archive log current;
System altered.
ZLM@ora10g> select group#,thread#,status,archived from v$log;
GROUP# THREAD# STATUS ARC
---------- ---------- ---------------- ---
1 1 ACTIVE YES
2 1 INACTIVE YES
3 1 CURRENT NO
--正常关闭数据库
ZLM@ora10g> shutdown immediate
ORA-01031: insufficient privileges
ZLM@ora10g> conn / as sysdba
Connected.
SYS@ora10g> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SYS@ora10g>
--OS上删除current的在线日志文件redo03.log
[oracle@ora10g ~]$ cd /u01/app/oracle/oradata/ora10g
[oracle@ora10g ora10g]$ ls -l
total 1461348
-rw-r----- 1 oracle oinstall 7520256 Jun 24 11:03 control01.ctl
-rw-r----- 1 oracle oinstall 7520256 Jun 24 11:03 control02.ctl
-rw-r----- 1 oracle oinstall 7520256 Jun 24 11:03 control03.ctl
-rw-r----- 1 oracle oinstall 104865792 Jun 24 11:03 example01.dbf
-rw-r----- 1 oracle oinstall 172032 Nov 29 2014 indx01.dbf
-rw-r----- 1 oracle oinstall 52429312 Jun 24 11:02 redo01.log
-rw-r----- 1 oracle oinstall 52429312 Jun 24 10:49 redo02.log
-rw-r----- 1 oracle oinstall 52429312 Jun 24 11:03 redo03.log
-rw-r----- 1 oracle oinstall 283123712 Jun 24 11:03 sysaux01.dbf
-rw-r----- 1 oracle oinstall 587210752 Jun 24 11:03 system01.dbf
-rw-r----- 1 oracle oinstall 52436992 Jun 23 16:17 temp01.dbf
-rw-r----- 1 oracle oinstall 173023232 Jun 24 11:03 undotbs01.dbf
-rw-r----- 1 oracle oinstall 41951232 Jun 24 11:03 users01.dbf
-rw-r----- 1 oracle oinstall 100671488 Jun 24 11:03 zlm01.dbf
[oracle@ora10g ora10g]$ rm -f redo03.log
[oracle@ora10g ora10g]$ ls -l redo*
-rw-r----- 1 oracle oinstall 52429312 Jun 24 11:02 redo01.log
-rw-r----- 1 oracle oinstall 52429312 Jun 24 10:49 redo02.log
[oracle@ora10g ora10g]$
--启动数据库
SYS@ora10g> startup
ORACLE instance started.