How to rename element (node) names in an XMLType column?

Question

I have a source table with a xml data stored in an XMLType column.
The xml contains elements/nodes identified by numbers. I need to replace the numbers with the appropriate names.
The plsql below does this, but has two issues:
i. It selects the data into a clob and does a text replace on the elements in a loop. This works, but is super slow for 3500+ xml rows (about 500 node pairs per row).
ii. Once the data has had the element numbers replaced with the names, it inserts the new xml (clob wrapped in xmltype function) into the table with the XMLType attribute.
The problem with the latter action is that it is failing due to nls client vs server settings, or so it appears from what I could dig up. The actual error message:
ORA-19202: Error occurred in XML processing
LPX-00242: invalid use of ampersand ('&') character (use &)
Error at line 3
There are come entities in the original xml like "" (the degree symbol).
My question is two-fold:
a). Can I replace the element names without straying from the xmltype datatype? If so, how?
b). If I cannot do "a.)", then what must I do ensure that the clob gets converted correctly to xmltype and inserted into the table?
SQL> select <some rows> from nls_database_parameters ;
PARAMETER VALUE
NLS_LANGUAGE AMERICAN
NLS_TERRITORY AMERICA
NLS_CHARACTERSET WE8ISO8859P1
NLS_NCHAR_CHARACTERSET AL16UTF16
NLS_RDBMS_VERSION 10.2.0.1.0
SQL> SELECT * FROM NLS_SESSION_PARAMETERS;
PARAMETER VALUE
NLS_LANGUAGE AMERICAN
NLS_TERRITORY AMERICA
----code below-----
(note, this is a stripped down version of the original, so there may be typos)
declare
l_xmlclob CLOB;
l_newxml XMLType;
v_record_uid NUMBER(20);
CURSOR my_cur IS
select a.elementname,b.tagname
from t_elements a, t_tags b
where (a.element_uid = b.element_uid)
begin
select br.xml_data.getClobVal() xml_data into l_xmlclob from t_elements;
FOR my_rec IN my_cur LOOP
l_xmlclob := replace(l_xmlclob,my_cur.elementname,my_cur.maptag_name);
END LOOP;
l_newxml := XMLType(l_xmlclob);
insert into test_translated_xml (xml_data) values (l_newxml);
end;
(hopefully I haven't missed anything)
Any tips or hints would be much appreciated.
Thanks!

Answer 1

Hello again,
Take a look at html entity codes: http://www.w3schools.com/tags/ref_entities.asp.
You can use this:
insert into t values (xmltype('<test>'||dbms_xmlgen.convert('this is a test &')||'deg;</test>'));
or
insert into t values (xmltype('<test>'||dbms_xmlgen.convert('this is a test &')||'#176;</test>'));
see this: &deg; (& deg;) or this: &#176; (& #176;)
SQL*Plus will not display degree character. But this is valid enitity code, and when you generate HTML out of this, it should be displayed properly in web browser.
HTML is in fact XML, that is validated by specific DTD (Document Type Definition).
Paweł