Java executed SQL statement to XML - large number of rows

Question

Hello,
I have to write some code to generate XML as the result of a query. AFAIK I am using the latest versions of the relevant Java libraries etc.
I have found that using a max_size function above 2000 results in 'Exception in thread "main" java.lang.OutOfMemoryError' errors
I thought I could overcome this by reading the data in batches using the skip_rows functionality.
I have included the code I am using below and would appreciate any help.
Best Regards,
Mark Robbins
import java.sql.*;
import java.math.*;
import oracle.xml.sql.query.*;
import oracle.xml.sql.docgen.*;
import oracle.jdbc.*;
import oracle.jdbc.driver.*;
public class XMLRetr
public static void main(String args[]) throws SQLException
String tabName = "becc";
String user = "test/test";
DriverManager.registerDriver(new oracle.jdbc.driver.OracleDriver());
//initiate a JDBC connection
Connection conn =
DriverManager.getConnection("jdbc:oracle:oci8:"+user+"@test");
// initialize the OracleXMLQuery
OracleXMLQuery qry = new OracleXMLQuery(conn,"select * from "+tabName+" where TRUNC(SAMPLED) < \'14-NOV-99\'" );
// structure the generated XML document
System.out.println("Before setting parameters");
qry.setMaxRows(8000); // set the maximum number of rows to be returned
qry.setRowsetTag("ROOTDOC"); // set the root document tag
qry.setRowTag("DBROW"); // sets the row separator tag
qry.setRaiseException(true);
qry.keepCursorState(true);
// create the document generation factory. Note: there are methods in OracleXMLQuery
// which don't require that an OracleXMLDocGen object be passed in; but rather, they
// create an OracleXMLDocGen object of their own.
OracleXMLDocGen doc = (OracleXMLDocGen) new OracleXMLDocGenString();
for (int rowCnt = 1; rowCnt < 8000; rowCnt = rowCnt + 1000)
// get the xml
System.out.println("Before skip rowCnt:"+rowCnt);
qry.setSkipRows(rowCnt); // process next batch
System.out.println("Before getXML");
// this is where I get the exception on the second iteration of the loop
qry.getXML(doc);
System.out.println("Displaying document");
// System.out.println(doc.getXMLDocumentString());
System.out.println("Row number:"+rowCnt);
System.out.flush();
System.out.println("End of document");
qry.close();
null

Answer 1

I used qry.getXMLString()
But called it for every row, ie, set
qry.maxRows(1) and qry.skipRows(rowcount-1).
The down side is I had to postprocess the String to remove the processing instruction and doc level tags.