Oracle Database Tips by Donald Burleson

Oracle10g Grid Computing with RAC
Chapter 8 - RAC Administration

Oracle Managed Files

The following initialization parameters specify the file location:

• db_create_file_dest: Defines the location of the default file system directory where Oracle creates data files or temp files (when no file specification is given in the object creation statement).
   

• db_create_online_log_dest_n: Defines the location of the default file system directory for online redo log files and control files when no file specification is given in the creation statement. You can use this initialization parameter multiple §            times where n specifies a multiplexed copy of the online redo log or control file.

Note that the file system directory specified by either of these parameters must already exist. Oracle does not create it. The directory must also have permissions to allow Oracle to create the files in it. The default location is used whenever a location is not explicitly specified for the operation of creating a file. Oracle creates the filename, and a file thus created is an Oracle-managed file. The following example sets /u01/oracle/data/applic as the default directory to use when creating Oracle-managed files:

DB_CREATE_FILE_DEST = '/u01/oracle/data/applic'

By default, this location would be applicable for data files, temp files, Online redo log files, and control files. However, you can include the db_create_online_log_dest_n initialization parameter in your initialization parameter file to identify the default location for the database server to create online redoes log files and control files. For example: