Reorganizing in NOARCHIVELOG Mode 

  1. We recommend performing an online or offline backup of the entire database.

    2. A complete backup of the database is not required if all redo logs since the last backup are available. If this is the case, it is sufficient for security purposes to use the ORACLE command ALTER SYSTEM SWITCH LOGFILE to force redo log file switching. This means that the online redo log files, which were not yet backed up by ARCH (this normally only concerns the current online redo log group), can also be written in the archiving directory.

  2. Shut down the database.
  3. Deactivate the ARCHIVELOG mode. To do this, use the SAPDBA function or the ORACLE command alter database noarchivelog (see SAPDBA: Archive Mode).
  4. You can now carry out the required reorganization.
  5. Once the reorganization is complete, you must reactivate the ARCHIVELOG mode.
  6. It is essential that you now perform a complete backup of the database, since recovering the database with an old backup would only possible to the state before the reorganization (remember that the reorganization was not performed in ARCHIVELOG mode).

Only an immediate offline backup can offer complete security. It is therefore best to start an offline backup of the entire database.

Although an online backup is possible, it conceals a certain risk if every data file was not backed up. If the online backup - for any reason - terminates, a recovery can only proceed to the state before the reorganization (starting from the last backup before the start of the reorganization). All changes made in the database during the online backup would be lost and would have to be repeated after the reorganization.