Need help on Unpivot (Columns to rows conversion)

Question

Could you please help me to do unpivot using sql?
Table creation and insertion scripts:
create table REQ
ID NUMBER,
VALUE VARCHAR2(20)
insert into REQ (ID, VALUE)
values (1, 'HI,HELLO, KARTHI');
insert into REQ (ID, VALUE)
values (2, 'ARE,YOU,FINE,BHAR');
insert into REQ (ID, VALUE)
values (3, '100,200,300');
commit;
I need to view the data in the below format
ID VALUE
1 HI
1 HELLO
1 KARTHI
2 ARE
2 YOU
2 FINE
2 BHAR
3 100
3 200
3 300

Answer 1

However, I would take care on the performance issue.So let's use the model clause:
SQL> set autotrace on
SQL> select id
  2       , v
  3    from req
  4   model
  5         partition by (id)
  6         dimension by (0 i)
  7         measures (value v)
  8         rules iterate (10) until (instr(v[iteration_number+1],',') = 0)
  9         ( v[iteration_number+1] = substr(v[iteration_number],instr(v[iteration_number],',')+1)
10         , v[iteration_number] = substr(v[iteration_number],1,instr(v[iteration_number],',')-1)
11         )
12   order by id
13       , i
14  /
                                    ID V
                                     1 HI
                                     1 HELLO
                                     1  KARTHI
                                     2 ARE
                                     2 YOU
                                     2 FINE
                                     2 BHAR
                                     3 100
                                     3 200
                                     3 300
10 rijen zijn geselecteerd.
Uitvoeringspan
   0      SELECT STATEMENT Optimizer=ALL_ROWS (Cost=3 Card=3 Bytes=75)
   1    0   SORT (ORDER BY) (Cost=3 Card=3 Bytes=75)
   2    1     SQL MODEL (ORDERED FAST) (Cost=3 Card=3 Bytes=75)
   3    2       TABLE ACCESS (FULL) OF 'REQ' (TABLE) (Cost=2 Card=3 By
          tes=75)
Statistics
         48  recursive calls
          0  db block gets
         11  consistent gets
          0  physical reads
          0  redo size
        528  bytes sent via SQL*Net to client
        271  bytes received via SQL*Net from client
          6  SQL*Net roundtrips to/from client
          1  sorts (memory)
          0  sorts (disk)
         10  rows processedRegards,
Rob.