Yes, it look's like the string parameter gets converted to a number. Told you it had changed. ;-)

Which means that

SQL> select count(*) from rdf_test where '1.0' = v1;

  COUNT(*)
----------
         1

SQL>  select count(*) from rdf_test where 'a' = v1;
 select count(*) from rdf_test where 'a' = v1
                                     *
ERROR at line 1:
ORA-01722: invalid number


SQL> select count(*) from rdf_test where v1 = 'a';
select count(*) from rdf_test where v1 = 'a'
                                         *
ERROR at line 1:
ORA-01722: invalid number
[download]

Obviously the fix is to convert the number into a string (since the exception can't be generated then). Thus,

  1* select count(*) from rdf_test where 'a' = TO_CHAR(v1)
SQL> /

  COUNT(*)
----------
         0
[download]

Great. It's working fine now. But...

SQL> select count(*) from rdf_test where '1.0' = TO_CHAR(v1);

  COUNT(*)
----------
         0
[download]

which leaves it still being a headache.

--
Tommy
Too stupid to live.
Too stubborn to die.