Total System Global Area 3207790592 bytes
Fixed Size 2119072 bytes
Variable Size 381586016 bytes
Database Buffers 2818572288 bytes
Redo Buffers 5513216 bytes
Database mounted.
SQL> alter session set events '10015 trace name adjust_scn level 11914';
Session altered.
SQL> select substr(checkpoint_change#,1,14) as df_scn from v$datafile;
DF_SCN
--------------------------------------------------------
12792226298122
12792226298122
12792226298122
12792226298122
12792226298122
12792226298122
12792226298122
12792226298122
12792226298122
12792226298122
12792226298122
DF_SCN
--------------------------------------------------------
12792226298122
12792226298122
13 rows selected.
SQL> select substr(checkpoint_change#,1,14) as dfh_scn from v$datafile;
DFH_SCN
--------------------------------------------------------
12792226298122
12792226298122
12792226298122
12792226298122
12792226298122
12792226298122
12792226298122
12792226298122
12792226298122
12792226298122
12792226298122
DFH_SCN
--------------------------------------------------------
12792226298122
12792226298122
13 rows selected.
SQL> alter database open;
Database altered.
场景二：
+++++Session 1
SQL> conn /as sysdba
Connected.
SQL> set lines 200
SQL> col member for a60
SQL> select * from v$Log;
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ---------
1 1 7 10485760 1 NO CURRENT 1073767933 22-JUL-13
2 1 5 10485760 1 YES INACTIVE 1073742213 21-JUL-13
3 1 6 52428800 1 YES INACTIVE 1073742215 21-JUL-13
SQL> select * from v$logfile;
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ------------------------------------------------------------ ---
2 ONLINE /home/ora10g/oradata/roger/redo02.log NO
3 ONLINE /home/ora10g/oradata/roger/redo03.log NO
1 ONLINE /home/ora10g/oradata/roger/redo01.log NO
SQL>
SQL> alter system switch logfile;
System altered.
++++Session 2
[ora10g@killdb ~]$ dd if=/dev/null of=/home/ora10g/oradata/roger/redo02.log bs=512 count=10
0+0 records in
0+0 records out
++++Session 1
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.
Total System Global Area 167772160 bytes
Fixed Size 1272600 bytes
Variable Size 96470248 bytes
Database Buffers 67108864 bytes
Redo Buffers 2920448 bytes
Database mounted.
ORA-00327: log 2 of thread 1, physical size less than needed
ORA-00312: online log 2 thread 1: '/home/ora10g/oradata/roger/redo02.log'
SQL> select * from v$Log;
GROUP# THREAD# SEQUENCE# BYTES MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIM
---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ---------
1 1 7 10485760 1 YES INACTIVE 1073767933 22-JUL-13
3 1 6 52428800 1 YES INACTIVE 1073742215 21-JUL-13
2 1 8 10485760 1 NO CURRENT 1073770766 22-JUL-13
SQL> recover database until cancel;
Media recovery complete.
SQL> alter database open resetlogs;
alter database open resetlogs
*
ERROR at line 1:
ORA-00327: log 2 of thread 1, physical size less than needed
ORA-00312: online log 2 thread 1: '/home/ora10g/oradata/roger/redo02.log'
在pfile文件中加入两个参数：
*._allow_resetlogs_corruption=true
*._allow_error_simulation=true
SQL> startup mount pfile='/tmp/pfile.ora';
ORACLE instance started.
Total System Global Area 167772160 bytes
Fixed Size 1272600 bytes
Variable Size 96470248 bytes
Database Buffers 67108864 bytes
Redo Buffers 2920448 bytes
Database mounted.