Wpg_docload fails with "large" files

Question

Hi people,
I have an application that allows the user to query and download files stored in an external application server that exposes its functionality via webservices. There's a lot of overhead involved:
1. The user queries the file from the application and gets a link that allows her to download the file. She clicks on it.
2. Oracle submits a request to the webservice and gets a XML response back. One of the elements of the XML response is an embedded XML document itself, and one of its elements is the file, encoded in base64.
3. The embedded XML document is extracted from the response, and the contents of the file are stored into a CLOB.
4. The CLOB is converted into a BLOB.
5. The BLOB is pushed to the client.
Problem is, it only works with "small" files, less than 50 KB. With "large" files (more than 50 KB), the user clicks on the download link and about one second later, gets a
The requested URL /apex/SCHEMA.GET_FILE was not found on this serverWhen I run the webservice outside Oracle, it works fine. I suppose it has to do with PGA/SGA tuning.
It looks a lot like the problem described at this Ask Tom question.
Here's my slightly modified code (XMLRPC_API is based on Jason Straub's excellent [Flexible Web Service API|http://jastraub.blogspot.com/2008/06/flexible-web-service-api.html]):
CREATE OR REPLACE PROCEDURE get_file ( p_file_id IN NUMBER )
IS
    l_url                  VARCHAR2( 255 );
    l_envelope             CLOB;
    l_xml                  XMLTYPE;
    l_xml_cooked           XMLTYPE;
    l_val                  CLOB;
    l_length               NUMBER;
    l_filename             VARCHAR2( 2000 );
    l_filename_with_path   VARCHAR2( 2000 );
    l_file_blob            BLOB;
BEGIN
    SELECT FILENAME, FILENAME_WITH_PATH
      INTO l_filename, l_filename_with_path
      FROM MY_FILES
     WHERE FILE_ID = p_file_id;
    l_envelope := q'!<?xml version="1.0"?>!';
    l_envelope := l_envelope || '<methodCall>';
    l_envelope := l_envelope || '<methodName>getfile</methodName>';
    l_envelope := l_envelope || '<params>';
    l_envelope := l_envelope || '<param>';
    l_envelope := l_envelope || '<value><string>' || l_filename_with_path || '</string></value>';
    l_envelope := l_envelope || '</param>';
    l_envelope := l_envelope || '</params>';
    l_envelope := l_envelope || '</methodCall>';
    l_url := 'http://127.0.0.1/ws/xmlrpc_server.php';
    -- Download XML response from webservice. The file content is in an embedded XML document encoded in base64
    l_xml := XMLRPC_API.make_request( p_url      => l_url,
                                      p_envelope => l_envelope );
    -- Extract the embedded XML document from the XML response into a CLOB
    l_val := DBMS_XMLGEN.convert( l_xml.extract('/methodResponse/params/param/value/string/text()').getclobval(), 1 );
    -- Make a XML document out of the extracted CLOB
    l_xml := xmltype.createxml( l_val );
    -- Get the actual content of the file from the XML
    l_val := DBMS_XMLGEN.convert( l_xml.extract('/downloadResult/contents/text()').getclobval(), 1 );
    -- Convert from CLOB to BLOB
    l_file_blob := XMLRPC_API.clobbase642blob( l_val );
    -- Figure out how big the file is
    l_length    := DBMS_LOB.getlength( l_file_blob );
    -- Push the file to the client
    owa_util.mime_header( 'application/octet', FALSE );
    htp.p( 'Content-length: ' || l_length );
    htp.p( 'Content-Disposition: attachment;filename="' || l_filename || '"' );
    owa_util.http_header_close;
    wpg_docload.download_file( l_file_blob );
END get_file;
/I'm running XE, PGA is 200 MB, SGA is 800 MB. Any ideas?
Regards,
Georger

Answer 1

Script: http://www.indesignsecrets.com/downloads/MultiPageImporter2.5JJB.jsx.zip
It works great for files upto ~400 pages, when have more pages than that, is when I get the crash at around page 332 .
Thanks