ORA - 00313, ORA -00312

ORA -00313 : open failed for members of log group string of thread string

Cause: The online log cannot be opened. May not be able to find file.

Action: See accompanying errors and make log available.

ORA - 00312
ORA-00312: online log 1 thread 1: '/u01/TESTDB3/oraredo/redo1a.log'
ORA-00312: online log 1 thread 1: '/u01/TESTDB3/oraredo/redo1b.log'

The above errors pop whenever you try to start the database.

Cause: Either the log file has been removed or the log file has been corrupted.

Action: Follow the steps below -

SQL> starup mount;
SQL> select status from v$log where group#=1;
If the status is not current them simply drop the log file as below:
SQL>alter database drop logfile group 1;
If required create another logfile group.
SQL>alter database add logfile group 3 '/u01/TESTDB3/oraredo/redo3a.log' size 10M;
SQL> recover database until cancel;
SQLalter database open resetlogs;

Oracle Release number format Description

Major Database Release Number - The first digit is the most general identifier. It represents a major new version of the software that contains significant new functionality.

Database Maintenance Release Number - The second digit that represents the maintenance level. Some new features may be included.

Application Server Release Number - The third digit reflects the release level of the Oracle Application Server.

Component Specific Release Number - The fourth digit identifies a release level specific to a component. Different components can have different numbers in this position depending upon, for example, component patch sets or interim releases.

Platform Specific Release Number - The fifth digit identifies a platform - specific release number. Ususally this is a patch set.