SQL> DECLARE
  2    x          XMLTYPE :=
  3               xmlType('<DATA>
  4                          <LINE>A</LINE>
  5                          <LINE>B</LINE>
  6                          <LINE>C</LINE>
  7                          <LINE>D</LINE>
  8                        </DATA>');
  9    CountNode  NUMBER(4);
 10  BEGIN
 11    SELECT COUNT(ve.EXTRACT('/*').GetStringval()) INTO CountNode
 12    FROM TABLE(xmlSequence(EXTRACT(x,'/DATA/LINE'))) ve;
 13    dbms_Output.Put_Line('No. of nodes: '
 14                         ||CountNode);
 15    FOR i IN 1..CountNode LOOP
 16      dbms_Output.Put_Line(i
 17                           ||': '
 18                           ||x.EXTRACT('/DATA/LINE['
 19                                       ||i
 20                                       ||']').GetStringval());
 21    END LOOP;
 22  END;
 23  /
No. of nodes: 4
1: <LINE>A</LINE>

2: <LINE>B</LINE>

3: <LINE>C</LINE>

4: <LINE>D</LINE>

PL/SQL procedure successfully completed.

SQL> select decode(rownum, 1, 'No. of nodes: '||count(*) over ()||'
  2  ') || rownum || ': ' || column_value val
  3  from table(xmlsequence(extract(xmltype(
  4  '<DATA>
  5  <LINE>A</LINE>
  6  <LINE>B</LINE>
  7  <LINE>C</LINE>
  8  <LINE>D</LINE>
  9  </DATA>'),
 10  '/DATA/LINE'))) t
 11  /
VAL
-------------------------------------------------------
No. of nodes: 4
1: <LINE>A</LINE>
2: <LINE>B</LINE>
3: <LINE>C</LINE>
4: <LINE>D</LINE>

4 rows selected.