Retrieving lots of rows through XSQL servlet

Question

Hi Steve!
I am currently trying to break XSQL-servlet in order to have some proof of usability for our customers.
During one of these 'sessions' I discovered that the XSQL servlet throws me out with an exception error (out of memory) when I try to retrieve 70K+ rows from a table using the XSQL commandline utility. The same thing happens when requested through the webserver.
This is definitely something I would like to be able to do without problems and (preferably) without too much programming.
Do you know of an elegant way to handle this?
BTW: We are trying to write a plain-and-simple export-to-XML utility, which dumps all rows of a given table to an XML file which we can feed to the XMLLoader utility from your book (which is -by the way- a great book!!)
Would you be able to give us some suggestions?

Answer 1

Here's some working code:
import org.xml.sax.*;
import org.xml.sax.helpers.*;
import java.util.Stack;
import java.io.*;
public class ExampleContentHandler extends DefaultHandler {
PrintWriter p;
Stack s;
ExampleContentHandler(PrintWriter p) {
this.p = p;
public void startDocument() {
s = new Stack();
public void startElement(String uri,
String localName,
String qname,
Attributes attrs) throws SAXException {
s.push(qname);
p.print("<"+qname);
int numAttrs = attrs.getLength();
for (int j = 0; j < numAttrs; j++) {
p.print((new StringBuffer(" ")).append(attrs.getQName(j))
.append("='")
.append(attrs.getValue(j))
.append("'").toString());
p.print(">");
public void endElement(String uri,
String localName,
String qname) throws SAXException {
s.pop();
p.print("</"+qname+">");
public void characters(char[] p0, int p1, int p2) throws SAXException {
p.print(quote(new String(p0,p1, p2)));
public void endDocument() {
p.flush();
private String quote(String val)
StringBuffer s = new StringBuffer();
int len = val.length();
for (int i = 0; i < len; i++ )
char c = val.charAt(i);
switch (c)
case '\r':
s.append('\n');
break;
case '&':
s.append("&;");
break;
case '<':
s.append("<");
break;
case '>':
s.append(">");
break;
default:
s.append(c);
return s.toString();
import org.xml.sax.*;
import java.sql.*;
import java.io.*;
import oracle.xml.sql.query.*;
import oracle.xml.parser.v2.*;
class XMLForQueryResults {
public static void main (String arg[]) throws Exception {
Connection cn = ConnectionHelper.getConnection();
OracleXMLQuery q = new OracleXMLQuery(cn,
"SELECT empno as EmpNo, " +
" ename as Name, " +
" sal as Salary" +
" FROM emp WHERE empno = 7839");
String s = q.getXMLString();
StringReader sr = new StringReader(s);
SAXParser sp = new SAXParser();
PrintWriter p = new PrintWriter(System.out);
ContentHandler c = new ExampleContentHandler(p);
sp.setContentHandler(c);
sp.parse(sr);
q = new OracleXMLQuery(cn,
"SELECT empno as \"@EmpNo\", " +
" ename as Name, " +
" sal as Salary" +
" FROM emp WHERE empno = 7839");
p = new PrintWriter(System.out);
c = new ExampleContentHandler(p);
q.getXMLSAX(c);
cn.close();
}