To remove ASM Files

In order to delete RMAN backup files, which will have a type of "ARCHIVELOG"
and "BACKUPSET" the following two commands can be run and their output
spooled to separate files

COL gsql FORMAT a300
SET ECHO OFF
SET VERIFY OFF
SET HEADING OFF
SET FEEDBACK OFF
SET PAGESIZE 0
SET LINESIZE 600
SET TRIMSPOOL ON

--generates file list for ARCHIVELOG
SELECT 'alter diskgroup 'dg.name' drop file
''+'dg.name''SYS_CONNECT_BY_PATH(al.name,'/')''';'
FROM v$asm_alias al, v$asm_file fi, v$asm_diskgroup dg
WHERE al.file_number = fi.file_number(+)
AND al.group_number = dg.group_number
AND fi.type = 'ARCHIVELOG'
START WITH alias_index = 0
CONNECT BY PRIOR al.reference_index = al.parent_index
/

--generates file list for BACKUPSET
SELECT 'alter diskgroup 'dg.name' drop file
''+'dg.name''SYS_CONNECT_BY_PATH(al.name,'/')''';'
FROM v$asm_alias al, v$asm_file fi, v$asm_diskgroup dg
WHERE al.file_number = fi.file_number(+)
AND al.group_number = dg.group_number
AND fi.type = 'BACKUPSET'
START WITH alias_index = 0
CONNECT BY PRIOR al.reference_index = al.parent_index
/

--get database name
ACCEPT database PROMPT 'Enter the database name: '
--generates file list
SELECT 'ALTER DISKGROUP 'gname' DROP FILE '''full_path''';' gsql FROM
(SELECT CONCAT('+'gname, SYS_CONNECT_BY_PATH(aname,'/')) full_path, gname FROM
(SELECT g.name gname, a.parent_index pindex, a.name aname,
a.reference_index rindex, a.ALIAS_DIRECTORY adir
FROM v$asm_alias a, v$asm_diskgroup g
WHERE a.group_number = g.group_number)
WHERE adir='N'
START WITH (MOD(pindex, POWER(2, 24))) = 0
CONNECT BY PRIOR rindex = pindex)
WHERE full_path LIKE UPPER('%&database%');