Oracle Database: Lost redo log file no backup no archivelog

SQL> startup
ORACLE instance started.

Total System Global Area 4294967296 bytes
Fixed Size 1306568 bytes
Variable Size 2534150200 bytes
Database Buffers 1728053248 bytes
Redo Buffers 31457280 bytes
Database mounted.
ORA-00314: log 1 of thread 1, expected sequence# doesn't match
ORA-00312: online log 1 thread 1: '/opt/oracle/oradata_4/RedoLogFiles/log1.dbf'

Steps to bring up the database:

1- startup nomount;

2- alter database backup controlfile to trace as 'c:\control.txt';

3- Modify the file as

CREATE CONTROLFILE REUSE DATABASE "ORCL" NORESETLOGS NOARCHIVELOG

to

CREATE CONTROLFILE REUSE DATABASE "ORCL" RESETLOGS NOARCHIVELOG

and Remove the lines starting from the line "RECOVER DATABASE USING BACKUP CONTROLFILE" to the end.

4- Create initORCL.ora if its not present as:

   create pfile from spfile;

Modify the file and add the following hidden parameter:

_allow_resetlogs_corruption=TRUE

5- Shutdown immediate;

6- startup nomount pfile='$ORACLE_HOME/database/initORCL.ora';

7- Run the controlfile creation script:

@c:\control.txt

this will recreate the control files.

8- Shutdown abort;

9- startup mount;

10- alter database open resetlogs;

>>>>>>>>>>>>>>> Done :)

Finally don't forget to remove the added parameter.

Welcome to Oracle World and try to enable archivelog and take regular backups .............