Which two statements are true about Oracle Managed Files (OMF)?
A.
OMF cannot be used in a database that already has data files created with user-specified
directions.
B.
The file system directions that are specified by OMF parameters are created automatically.
C.
OMF can be used with ASM disk groups, as well as with raw devices, for better file
management.
D.
OMF automatically creates unique file names for table spaces and control files.
E.
OMF may affect the location of the redo log files and archived log files.
Explanation:
B: Through initialization parameters, you specify the file system directory to be used
for a particular type of file. The database then ensures that a unique file, an Oracle-managed file,
is created and deleted when no longer needed.
D: The database internally uses standard file system interfaces to create and delete files as
needed for the following database structures:
Tablespaces
Redo log files
Control files
Archived logs
Block change tracking files
Flashback logs
RMAN backups
Note:
* Using Oracle-managed files simplifies the administration of an Oracle Database. Oraclemanaged files eliminate the need for you, the DBA, to directly manage the operating system files
that make up an Oracle Database. With Oracle-managed files, you specify 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 datafile with the DATAFILE clause.
Reference: What Are Oracle-Managed Files?
Not A. New files can be created as managed files while old ones are administered in the old way. Thus, a database can have a mixture of Oracle-managed and unmanaged files.
Not B. The file system directory specified by either of these parameters must already exist: the database does not create it. The directory must also have permissions to allow the database to create the files in it.
Not C. The Oracle-managed files feature is not intended to ease administration of systems that use raw disks.
So DE
D – TRUE
Setting the DB_CREATE_FILE_DEST Initialization Parameter
– Datafiles
– Tempfiles
– Redo log files
– Control files
– Block change tracking files
E – TRUE
Setting the DB_RECOVERY_FILE_DEST Parameter
– Redo log files or multiplexed copies of redo log files
– Control files or multiplexed copies of control files
– RMAN backups (datafile copies, control file copies, backup pieces, control file autobackups)
– Archived logs
– Flashback logs
C – FALSE
The Oracle-managed files feature is not intended to ease administration of systems that use raw disks.
Since there is no operating system support for allocation of raw disks (it is done manually), this feature cannot help
doc from O11G
http://docs.oracle.com/cd/B28359_01/server.111/b28310/omf.htm
DE
D – is False Since That option telling us it will create unique name for Tablespaces but that is wrong OEM will create unique names for Datafiles in Tablespaces.
E – True
C- Is also True You can configure OMF for File systems as well.
DE – OK
C – FALSE – we canot use OMF with raw devices only with ASM
Not understanding how E can be correct. If you set DB_RECOVERY_FILE_DEST then OMF uses that location. I can’t find an example how how OMF would affect the location of anything because it uses the location you specify. Unless OMF can decide on its own to put files wherever it want to?
DE
DE
The Oracle-managed files feature is not intended to ease administration of systems that use raw disks. Hence, C is ruled out.
Each Oracle-managed file and filename is unique. Using the same file in two different databases is a common mistake that can cause very large down times and loss of committed transactions. Using two different names that refer to the same file is another mistake that causes major corruptions. Hence, D is a correct Choice.
Using Oracle-managed files does not eliminate any existing functionality. Existing databases are able to operate as they always have. New files can be created as managed files while old ones are administered in the old way. Thus, a database can have a mixture of Oracle-managed and unmanaged files. Choice A is not true. This can be ruled out.
B can be rule dout, as the OMF does not create the directories.
Hence correct anwers are: D, E
B – per below demo, it seems like creates the directory too
http://docs.oracle.com/cd/B10501_01/server.920/a96521/omf.htm
C – Is correct
E – Not sure what does it mean by effect the location of the redo log and archive.
DE
A is wrong
Using Oracle Managed Files does not eliminate any existing functionality. Existing databases are able to operate as they always have. New files can be created as managed files while old ones are administered in the old way. Thus, a database can have a mixture of Oracle managed and unmanaged files.
B is wrong
The file system directories specified by these parameters must already exist; the database does not create them. The directory must also have permissions to allow the database to create the files in it.
A) False
https://docs.oracle.com/database/121/ADMIN/omf.htm#ADMIN11487
Using Oracle Managed Files does not eliminate any existing functionality. Existing databases are able to operate as they always have. New files can be created as managed files while old ones are administered in the old way. Thus, a database can have a mixture of Oracle managed and unmanaged files.
B) False
https://docs.oracle.com/database/121/ADMIN/omf.htm#ADMIN11487
The file system directories specified by these parameters must already exist; the database does not create them. The directory must also have permissions to allow the database to create the files in it.
C) False -> Not Raw Devices
https://docs.oracle.com/database/121/ADMIN/omf.htm#ADMIN11487
Defines the location of the default file system directory or Oracle ASM disk group where the database creates data files or temp files when no file specification is given in the create operation.
D) True
The database internally uses standard file system interfaces to create and delete files as needed for the following database structures:
Tablespaces
Redo log files
Control files
Archived logs
Block change tracking files
Flashback logs
RMAN backups
Each Oracle managed file and filename is unique. Using the same file in two different databases is a common mistake that can cause very large down times and loss of committed transactions. Using two different names that refer to the same file is another mistake that causes major corruptions.
E) True
DB_CREATE_ONLINE_LOG_DEST_n
Defines the location of the default file system directory or Oracle ASM disk group for redo log files and control file creation when no file specification is given in the create operation. By changing n, you can use this initialization parameter multiple times, where n specifies a multiplexed copy of the redo log or control file. You can specify up to five multiplexed copies.
DB_RECOVERY_FILE_DEST
Defines the location of the Fast Recovery Area, which is the default file system directory or Oracle ASM disk group where the database creates RMAN backups when no format option is used, archived logs when no other local destination is configured, and flashback logs. Also used as the default location for redo log and control files or multiplexed copies of redo log and control files if DB_CREATE_ONLINE_LOG_DEST_n are not specified. When this parameter is specified, the DB_RECOVERY_FILE_DEST_SIZE initialization parameter must also be specified.
DE!!!
D (but it’s datafiles not tablespaces)
E