打开trace文件，修改里面的logfile部分信息；然后重启数据库到nomount状态；
sys@racdb3> shutdown immediate
SQL> STARTUP NOMOUNT
CREATE CONTROLFILE REUSE DATABASE "RACDB" RESETLOGS  ARCHIVELOG
MAXLOGFILES 50
MAXLOGMEMBERS 2
MAXDATAFILES 2000
MAXINSTANCES 8
MAXLOGHISTORY 292
LOGFILE
GROUP 1 '/app/oracle/oradata/group_1.263.779207025'  SIZE 10M，
GROUP 2 '/app/oracle/oradata/group_2.259.779207027'  SIZE 10M，
GROUP 3 '/app/oracle/oradata/group_3.258.779207027'  SIZE 10M
DATAFILE
'/app/oracle/oradata/system.257.779207027'，
'/app/oracle/oradata/undotbs1.264.779207043'，
'/app/oracle/oradata/sysaux.262.779207043'，
'/app/oracle/oradata/users.260.779207053'，
'/app/oracle/oradata/undotbs2.268.779207507'，
'/app/oracle/oradata/tbs_p1w.270.780396121'，
'/app/oracle/oradata/tbs_p2w.273.780396123'，
'/app/oracle/oradata/tbs_p3w.271.780396123'，
'/app/oracle/oradata/tbs_p4w.274.780396125'，
'/app/oracle/oradata/pptest_tbs.279.781454807'，
'/app/oracle/oradata/pptest_tbs.282.793979093'
CHARACTER SET ZHS16GBK
;
　　创建完成后，用backup controlfile进行恢复；
sys@racdb3> RECOVER DATABASE USING BACKUP CONTROLFILE until cancel;
sys@racdb3>ALTER DATABASE ADD LOGFILE THREAD 2
GROUP 4 '/app/oracle/oradata/group_4.265.779207453' SIZE 10M REUSE，
GROUP 5 '/app/oracle/oradata/group_5.266.779207459' SIZE 10M REUSE，
GROUP 6 '/app/oracle/oradata/group_6.267.779207467' SIZE 10M REUSE;
sys@racdb3> alter database open resetlogs;
成功resetlogs打开后，还需要做一些去thread 2的操作；
sys@racdb3> alter database disable thread 2;
sys@racdb3> alter database drop logfile group 4;
alter database drop logfile group 4
*
ERROR at line 1:
ORA-00350: log 4 of instance UNNAMED_INSTANCE_2 (thread 2) needs to be archived
ORA-00312: online log 4 thread 2: '/app/oracle/oradata/RACDB/onlinelog/o1_mf_4_9ym2kvgf_.log'
sys@racdb3> alter database clear unarchived logfile group 4;
sys@racdb3> alter tablespace temp add tempfile '/app/oracle/oradata/temp01.dbf' size 10M reuse;
Tablespace altered.
sys@racdb3> drop tablespace undotbs2 including contents and datafiles;