ASM

--Delete a directory and all its contents:
ALTER DISKGROUP DB_DATA DROP DIRECTORY '+DB_DATA/my_dir_2' FORCE;

--Aliases
--Aliases allow you to reference ASM files using user-friendly names, rather than the fully qualified ASM filenames.

--Create an alias using the fully qualified filename:
ALTER DISKGROUP DB_DATA ADD ALIAS '+DB_DATA/my_dir/my_file.dbf' FOR '+DB_DATA/mydb/datafile/my_ts.342.3';

--Create an alias using the numeric form filename:
ALTER DISKGROUP Db_DATA ADD ALIAS '+DB_DATA/my_dir/my_file.dbf' FOR '+DB_DATA.342.3';

--Rename an alias:
ALTER DISKGROUP DB_DATA RENAME ALIAS '+DB_DATA/my_dir/my_file.dbf' TO '+DB_DATA/my_dir/my_file2.dbf';

--Delete an alias:
ALTER DISKGROUP DB_DATA DELETE ALIAS '+DB_DATA/my_dir/my_file.dbf';

--Files
--Files are not deleted automatically if they are created using aliases, as they are not Oracle Managed Files (OMF), or if a recovery is done to a point-in-time before the file was created. For these circumstances it is necessary to manually delete the files, as shown below.

--Drop file using an alias:
ALTER DISKGROUP DB_DATA DROP FILE '+DB_DATA/my_dir/my_file.dbf';

--Drop file using a numeric form filename:
ALTER DISKGROUP Db_DATA DROP FILE '+DB_DATA.342.3';

--Drop file using a fully qualified filename:
ALTER DISKGROUP DB_DATA DROP FILE '+DB_DATA/mydb/datafile/my_ts.342.3';

--Metadata
--The internal consistency of disk group metadata can be checked in a number of ways using the CHECK clause of the ALTER DISKGROUP statement.

--Check metadata for a specific file:
ALTER DISKGROUP DB_DATA CHECK FILE '+DB_DATA/my_dir/my_file.dbf'

--Check metadata for a specific failure group in the disk group:
ALTER DISKGROUP DB_DATA CHECK FAILGROUP failure_group_1;

--Check metadata for a specific disk in the disk group:
ALTER DISKGROUP DB_DATA CHECK DISK diska1;

--Check metadata for all disks in the disk group:
ALTER DISKGROUP DB_DATA CHECK ALL;

--Templates
--Templates are named groups of attributes that can be applied to the files within a disk group. The following example show how templates can be created, altered and dropped.

--Create a new template:
ALTER DISKGROUP DB_DATA ADD TEMPLATE my_template ATTRIBUTES (MIRROR FINE);

--Modify template:
ALTER DISKGROUP DB_DATA ALTER TEMPLATE my_template ATTRIBUTES (COARSE);

--Drop template.
ALTER DISKGROUP DB_DATA DROP TEMPLATE my_template;