How can i drop the redolog File

Question

hello ,
I was installing oracle 10g on windows using DBCA. The problem is that i made three group of redolog size 1M. When DBCA was creating the database i got an error msg that "Size of redo log is less "But i ignored that error.
Ater that the database was created and i got a warning open the datbase using resetlogs.
The datbase is created but in Redolog file was not there(Physical files).
now i mounted the database. At that time the 3rd Redolog grp was active so i dropped the 1st n 2nd grp and created with 8MB.
but to drop 3rd grp i want swicth the logfile but without opening the datbase it is not possible.
and with the current size of 3rd redolog grp(Becoz of size) it is not possible to open the database.
So plz tell me how can i
1) How can i switch the logfile grp
2) drop the 3rd redolog group
thanx in advance
Ashish

Answer 1

Well, you can recreate ctlfile :
SQL> startup mount
ORACLE instance started.
Total System Global Area  135339876 bytes
Fixed Size                   454500 bytes
Variable Size             109051904 bytes
Database Buffers           25165824 bytes
Redo Buffers                 667648 bytes
Database mounted.
SQL> alter database backup controlfile to trace;
Database altered.
SQL> shutdown immediate
ORA-01109: database not open
Database dismounted.
ORACLE instance shut down.In the file generated, take the step #2, and change the size of redolog files. And run it :
SQL> CREATE CONTROLFILE REUSE DATABASE "DEMO9I" RESETLOGS  NOARCHIVELOG
  2  --  SET STANDBY TO MAXIMIZE PERFORMANCE
  3      MAXLOGFILES 50
  4      MAXLOGMEMBERS 5
  5      MAXDATAFILES 100
  6      MAXINSTANCES 1
  7      MAXLOGHISTORY 226
  8  LOGFILE
  9    GROUP 1 'E:\ORACLE\ORADATA\DEMO9I\REDO01.LOG'  SIZE 110M, --I changed it, it was 100M
10    GROUP 2 'E:\ORACLE\ORADATA\DEMO9I\REDO02.LOG'  SIZE 110M,--I changed it, it was 100M
11    GROUP 3 'E:\ORACLE\ORADATA\DEMO9I\REDO03.LOG'  SIZE 110M--I changed it, it was 100M
12  -- STANDBY LOGFILE
13  DATAFILE
14    'E:\ORACLE\ORADATA\DEMO9I\SYSTEM01.DBF',
15    'E:\ORACLE\ORADATA\DEMO9I\UNDOTBS01.DBF',
16    'E:\ORACLE\ORADATA\DEMO9I\CWMLITE01.DBF',
17    'E:\ORACLE\ORADATA\DEMO9I\DRSYS01.DBF',
18    'E:\ORACLE\ORADATA\DEMO9I\EXAMPLE01.DBF',
19    'E:\ORACLE\ORADATA\DEMO9I\INDX01.DBF',
20    'E:\ORACLE\ORADATA\DEMO9I\ODM01.DBF',
21    'E:\ORACLE\ORADATA\DEMO9I\TOOLS01.DBF',
22    'E:\ORACLE\ORADATA\DEMO9I\USERS01.DBF',
23    'E:\ORACLE\ORADATA\DEMO9I\XDB01.DBF',
24    'E:\ORACLE\ORADATA\DEMO9I\TBS_TST_01.DBF'
25  CHARACTER SET AL32UTF8
26  ;
Control file created.
SQL> ALTER DATABASE OPEN RESETLOGS;
Database altered.
SQL> ALTER TABLESPACE TEMP ADD TEMPFILE 'E:\ORACLE\ORADATA\DEMO9I\TEMP01.DBF' REUSE;
Tablespace altered.
SQL> HTH,
Nicolas.