Oracle Managed Files

OMF

In Oracle Database there is User Managed Files(UMF) which are created by the DBA as shown in the below example.

Oracle Managed Files are created by Oracle. Oracle Database can manage the files that comprise the database. Oracle Managed Files eases database administration, reduces errors, and reduces wasted disk space.Using Oracle Managed Files simplifies the administration of an Oracle Database. Oracle Managed Files eliminates the need for you, the DBA, to directly manage the operating system files that comprise an Oracle Database.

For this we need to specify the file system directories in which the database automatically creates, names, and manages files at the database object level. For example, you need only specify that you want to create a tablespace; you do not need to specify the name and path of the tablespace's data file with the DATAFILE clause. This feature works well with a logical volume manager (LVM). To use OMF we need to specify/ set the parameter as shown below.

If the value of db_create_file_dest is null, we can understand the OMF management is not enabled. To enable and to store the OMF files creating a directory to set file_destination.

If we don't give db_online_log_dest location for Control files and Redo log files. Those will be created under the File_destination only. We can give db_online_log_dest_(1 to 5) upto 5 locations.