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Adding Log Files - OMF

Notes:

This example demonstrates the use of the Oracle9i feature Oracle Managed Files (OMF) to add OMF-managed redo logs.
First, insure the DB_CREATE_ONLINE_DEST_n parameters are set correctly. DB_CREATE_ONLINE_DEST_n specifies the location of the online logs. Up to 5 can be specified so that, like the archive logs, you can multiplex the online logs.
In this example, when the ALTER SYSTEM ADD LOGFILE command is issued, Oracle creates two logs – mirror images of each other – of 100Mb in size.
Be sure that all the online logs are the same size. Tuning is made more difficult (impossible?) is the logs are different sizes. Add the SIZE parameter to the ALTER SYSTEM command if the database does not use 100Mb log files:
ALTER SYSTEM ADD LOGFILE SIZE 50M;
Turn to the next page for more information on multiplexing the online logs.