Why can't owa_text.vc_arr handle the string with more than 4000 characters?

Question

I am using PL_SQL with Oracle8i and OAS 4.0 web server.I want to
use owa_text.vc_arr to pass the inputs in serval text areas in the form on a web application.
If the input string length is less than 4000 characters, everything works fine.However when the strings are longer than 4000 characters but less than the max length 32767 characters, I got this error message:
OWS-05101: Execution failed due to Oracle error 2005
ORA-02005: implicit (-1) length not valid for this bind or define datatype.
In the Oracle Application Server 4.0 documment, it says
about owa_text.vc_arr :Type vc_arr is table of varchar2(32767)
index by binary_integer. It means that owa_text.vc_arr can handle multiple strings and each string can have up to 32767 single byte characters, is it right?
Owa_text.vc_arr is supposed to handle the string with more
than 4000 characters, is it true? Could anyone tell me why? Any
help will be greatly appreciated!!!
Thanks very much.
Helena Wang
Here is the pl_sql procedure to create my form on the web:
PROCEDURE myform
IS
BEGIN
htp.p('
<form action="'||service_path||'helena_test.saveform3"
method=post>
<input type=hidden name=tdescription value="X">
Input1: <textarea name=tdescription rows=50 cols=70
WRAP=physical></textarea>
Input2: <textarea name=tdescription rows=50 cols=70
WRAP=physical></textarea>
<input type=submit name=WSave value="Save">
</form>
END;
/***** here is the pl_sql procedure which I use to save the
form***/
procedure saveform3(tdescription in owa_text.vc_arr,
WSave in varchar2 default 'No')
is
len pls_integer;
begin
for i in 2..tdescription.count loop
len := length(tdescription(i));
htp.p(len);
htp.p(tdescription(i));
end loop;
end;

Answer 1

The maximum size of a VARCHAR2 field in Oracle 8i is 4000 bytes.
you'll ned to use a LOB type (or LONG if you prefer the old way)