oracle get partition name by high value

1-- Sortable (by high_value) list of partitions / subpartitions in a table
2-- For partitions, change ALL_TAB_SUBPARTITIONS to ALL_TAB_PARTITIONS
3SELECT TABLE_NAME, PARTITION_NAME, SUBPARTITION_NAME, HIGH_VALUE FROM (
4    WITH xml_s AS (
5        SELECT dbms_xmlgen.getxmltype('SELECT TABLE_NAME,PARTITION_NAME,
6          SUBPARTITION_NAME, HIGH_VALUE 
7          FROM ALL_TAB_SUBPARTITIONS WHERE TABLE_NAME=''MY_TABLE'' 
8          AND TABLE_OWNER=''MY_USER''') as x
9          FROM dual
10    )
11    SELECT xmltab.* FROM
12      xml_s,
13      xmltable(
14        '/ROWSET/ROW' passing xml_s.x columns
15          TABLE_NAME varchar2(30) path 'TABLE_NAME',
16          PARTITION_NAME  varchar2(30)  path 'PARTITION_NAME',
17          SUBPARTITION_NAME  varchar2(30)  path 'SUBPARTITION_NAME',
18          HIGH_VALUE varchar2(200) path 'HIGH_VALUE'
19      ) xmltab
20    ORDER BY TABLE_NAME, PARTITION_NAME, SUBPARTITION_NAME, HIGH_VALUE
21);