SQL & PL/SQL

Greetings,

I have the following code segment (for simplicity I have removed the writes to file which are used for testing results) -

set serveroutput on
DECLARE
V2 CLOB;
cursor c_clob is
select c10
from bill_t392;
BEGIN
open c_clob;
loop
exit when c_clob%NOTFOUND;
fetch c_clob into V2;
V2 := REGEXP_REPLACE(V2,'110300','XXXXXXXXXXXX');
end loop;
commit;
close c_clob;
end;
/

The table bill_t392 is a small table, only 96 records. I write out the value of V2 immediately after the REGEXP_REPLACE command executes and see that in fact V2 has been updated properly. But after the procedure completes the SQL statement -

select c10 from bill_t392
where regexp_like (c10,'XXXXXXXX')
/

returns no rows but the statement

select c10 from bill_t392
where regexp_like (c10,'110300')
/

does return the original row unchanged. I am puzzled as it appears that the change is only in effect during the execution of the procedure and that the commit doesn't take place. I'm sure I am missing something but can't find it. Any suggestions greatly appreciated.

Thanks
Bill Wagman