实验记录：Oracle redo logfile的resize过程。
实验环境：RHEL 6.4 + Oracle 11.2.0.3 单实例 文件系统
实验目的：本实验是修改redo logfile的过程记录，将当前数据库的3组redo logfile由原来的默认50M大小修改为100M。
1.查看当前redo logfile的信息
SQL> set linesize 160
SQL> col member for a60
SQL> select * from v$logfile;
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ------------------------------------------------------------ ---
3 ONLINE /home/oradata/JYZHAO/onlinelog/o1_mf_3_9n7r40xm_.log NO
3 ONLINE /u01/app/oracle/fast_recovery_area/JYZHAO/onlinelog/o1_mf_3_ YES
9n7r412h_.log
2 ONLINE /home/oradata/JYZHAO/onlinelog/o1_mf_2_9n7r3zyv_.log NO
2 ONLINE /u01/app/oracle/fast_recovery_area/JYZHAO/onlinelog/o1_mf_2_ YES
9n7r403z_.log
1 ONLINE /home/oradata/JYZHAO/onlinelog/o1_mf_1_9n7r3z5p_.log NO
1 ONLINE /u01/app/oracle/fast_recovery_area/JYZHAO/onlinelog/o1_mf_1_ YES
9n7r3zb8_.log
GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ------------------------------------------------------------ ---
6 rows selected.
SQL> !
[oracle@JY-DB dbhome_1]$ ls -lh /home/oradata/JYZHAO/onlinelog/
total 151M
-rw-r-----. 1 oracle oinstall 51M Jun 10 22:02 o1_mf_1_9n7r3z5p_.log
-rw-r-----. 1 oracle oinstall 51M Jun 10 22:34 o1_mf_2_9n7r3zyv_.log
-rw-r-----. 1 oracle oinstall 51M Jun 10 18:00 o1_mf_3_9n7r40xm_.log
[oracle@JY-DB dbhome_1]$ ls -lh /u01/app/oracle/fast_recovery_area/JYZHAO/onlinelog/
total 151M
-rw-r-----. 1 oracle oinstall 51M Jun 10 22:02 o1_mf_1_9n7r3zb8_.log
-rw-r-----. 1 oracle oinstall 51M Jun 10 22:34 o1_mf_2_9n7r403z_.log
-rw-r-----. 1 oracle oinstall 51M Jun 10 18:00 o1_mf_3_9n7r412h_.log
[oracle@JY-DB dbhome_1]$ exit
exit
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------------- ------------ -------------------
1 1 883 52428800 512 2 YES INACTIVE 12388912 2014-06-10 18:00:06 12407579 2014-06-10 22:02:06
2 1 884 52428800 512 2 NO CURRENT 12407579 2014-06-10 22:02:06 2.8147E+14
3 1 882 52428800 512 2 YES INACTIVE 12388904 2014-06-10 18:00:06 12388912 2014-06-10 18:00:06
2.删除redo日志文件组1（确定group1的状态为INACTIVE）
SQL> alter database drop logfile group 1;
Database altered.
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------------- ------------ -------------------
2 1 884 52428800 512 2 NO CURRENT 12407579 2014-06-10 22:02:06 2.8147E+14
3 1 882 52428800 512 2 YES INACTIVE 12388904 2014-06-10 18:00:06 12388912 2014-06-10 18:00:06
SQL> !
[oracle@JY-DB dbhome_1]$ ls -lh /home/oradata/JYZHAO/onlinelog/
total 101M
-rw-r-----. 1 oracle oinstall 51M Jun 10 22:37 o1_mf_2_9n7r3zyv_.log
-rw-r-----. 1 oracle oinstall 51M Jun 10 18:00 o1_mf_3_9n7r40xm_.log
[oracle@JY-DB dbhome_1]$ ls -lh /u01/app/oracle/fast_recovery_area/JYZHAO/onlinelog/
total 101M
-rw-r-----. 1 oracle oinstall 51M Jun 10 22:37 o1_mf_2_9n7r403z_.log
-rw-r-----. 1 oracle oinstall 51M Jun 10 18:00 o1_mf_3_9n7r412h_.log
--可以看到数据库执行删除日志组1的命令后，日志组1对应的系统文件也会被自动删除。
3. 添加日志组1和成员
[oracle@JY-DB dbhome_1]$ exit
exit
SQL> alter database add logfile group 1 '/home/oradata/JYZHAO/onlinelog/redo01a.log' size 100M;
Database altered.
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------------- ------------ -------------------
1 1 0 104857600 512 1 YES UNUSED 0 0
2 1 884 52428800 512 2 NO CURRENT 12407579 2014-06-10 22:02:06 2.8147E+14
3 1 882 52428800 512 2 YES INACTIVE 12388904 2014-06-10 18:00:06 12388912 2014-06-10 18:00:06
SQL> alter database add logfile member '/u01/app/oracle/fast_recovery_area/JYZHAO/onlinelog/redo01b.log' to group 1;
Database altered.
4.手工切换日志以应用新加的日志文件组
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------------- ------------ -------------------
1 1 0 104857600 512 2 YES UNUSED 0 0
2 1 884 52428800 512 2 NO CURRENT 12407579 2014-06-10 22:02:06 2.8147E+14
3 1 882 52428800 512 2 YES INACTIVE 12388904 2014-06-10 18:00:06 12388912 2014-06-10 18:00:06
SQL> alter system switch logfile;
System altered.
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------------- ------------ -------------------
1 1 885 104857600 512 2 NO CURRENT 12410983 2014-06-10 22:44:14 2.8147E+14
2 1 884 52428800 512 2 YES ACTIVE 12407579 2014-06-10 22:02:06 12410983 2014-06-10 22:44:14
3 1 882 52428800 512 2 YES INACTIVE 12388904 2014-06-10 18:00:06 12388912 2014-06-10 18:00:06
5.手工checkpoint让ACTIVE状态的日志文件组变成INACTIVE。
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------------- ------------ -------------------
1 1 885 104857600 512 2 YES INACTIVE 12410983 2014-06-10 22:44:14 12411004 2014-06-10 22:45:03
2 1 887 104857600 512 2 NO CURRENT 12411270 2014-06-10 22:51:39 2.8147E+14
3 1 886 52428800 512 2 YES ACTIVE 12411004 2014-06-10 22:45:03 12411270 2014-06-10 22:51:39
SQL> alter system checkpoint;
System altered.
SQL> select * from v$log;
GROUP# THREAD# SEQUENCE# BYTES BLOCKSIZE MEMBERS ARC STATUS FIRST_CHANGE# FIRST_TIME NEXT_CHANGE# NEXT_TIME
---------- ---------- ---------- ---------- ---------- ---------- --- ---------------- ------------- ------------------- ------------ -------------------
1 1 885 104857600 512 2 YES INACTIVE 12410983 2014-06-10 22:44:14 12411004 2014-06-10 22:45:03
2 1 887 104857600 512 2 NO CURRENT 12411270 2014-06-10 22:51:39 2.8147E+14
3 1 886 52428800 512 2 YES INACTIVE 12411004 2014-06-10 22:45:03 12411270 2014-06-10 22:51:39
6.参照上述步骤完成其他redo日志文件大小的resize，不再赘述。