Relocating redo log files (修改日志文件路径)

修改日志文件路径，实现多路径，虽然这会降低性能，但与数据的安全性相比，是值得的！还有数据优化中记的把redo log 与数据文件分开，而且要把redo log放在最快的硬盘设备上，实现 减轻io负载
SQL> select * from v$logfile;

GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ---------------------------------------------------------------------- ---
3 ONLINE /oradata/ahjcyl/redo03_1.log NO
3 ONLINE /oracle/oradata/ahjcyl/redo03_2.log NO
2 ONLINE /oracle/oradata/ahjcyl/redo02_1.log NO
2 ONLINE /oracle/oradata/ahjcyl/redo02_2.log NO
1 ONLINE /oradata/ahjcyl/redo01_1.log NO
1 ONLINE /oracle/oradata/ahjcyl/redo01_2.log NO

6 rows selected.
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> starup mount
SP2-0734: unknown command beginning "starup mou..." - rest of line ignored.
SQL> startup mount
ORACLE instance started.

Total System Global Area 1610612736 bytes
Fixed Size 2084296 bytes
Variable Size 385876536 bytes
Database Buffers 1207959552 bytes
Redo Buffers 14692352 bytes
Database mounted.
SQL> host
[oracle@ahjcyl-db ahjcyl]$ cp /oracle/oradata/ahjcyl/redo02_1.log /oradata/ahjcyl/redo02_1.log
[oracle@ahjcyl-db ahjcyl]$ exit
exit

SQL> alter database rename file '/oracle/oradata/ahjcyl/redo02_1.log' to '/oradata/ahjcyl/redo02_1.log'
2 ;

Database altered.

SQL> alter database open;

Database altered.

SQL> set linesize 150
SQL> col member for a70
SQL> select * from v$logfile;

GROUP# STATUS TYPE MEMBER IS_
---------- ------- ------- ---------------------------------------------------------------------- ---
3 ONLINE /oradata/ahjcyl/redo03_1.log NO
3 ONLINE /oracle/oradata/ahjcyl/redo03_2.log NO
2 ONLINE /oradata/ahjcyl/redo02_1.log NO
2 ONLINE /oracle/oradata/ahjcyl/redo02_2.log NO
1 ONLINE /oradata/ahjcyl/redo01_1.log NO
1 ONLINE /oracle/oradata/ahjcyl/redo01_2.log NO

6 rows selected.

SQL>