Try with

for (int j =3D 0; j <=3D 100; j++) {
sql =3D "SELECT * FROM " + TABLE_NAME + ";";
stmt =3D conn.createStatement();
ResultSet rs =3D stmt.executeQuery(sql);
while (rs.next()) {
rs.getString("col1");
}
rs.close();
stmt.close();=09
}

I think you must close ResultSet and Statement.

Andrea Sodomaco
www.sodomaco.it



-----Messaggio originale-----
Da: Przemyslaw Klein [mailto.klein (AT) ziaja (DOT) com]=20
Inviato: gioved=EC 23 febbraio 2006 12.48
A: java (AT) lists (DOT) mysql.com
Oggetto: java.lang.OutOfMemoryError - LONG (with test case)


Hi All.

This test case tries to perform following steps:
1. connect to database
2. create table with 9 columns - col1 int, col2 varchar(255), col3 text,

col4 int, col5 varchar(255), col6 text, col7 int, col8 varchar(255),=20
col9 text
3. populate it with 200 rows - same values=20
('1','2','3','4','5','6','7','8','9')
4. try to retrieve 'col1' from every row 300*100 times
5. disconnect from database

Unfortunately it throws java.lang.OutOfMemoryError during step 4. As you

can see, we don't store retrieved data, so we don't consume any memory.=20
We run this test under Borland OptimizeIt Profiler and ito shows that=20
99,9% memory consumes mysql connector.

MySQL server: mysql Ver 14.7 Distrib 4.1.10, for pc-linux-gnu (i686)
jdbc: mysql-connector-java-3.1.12-bin.jar

Thanks for any help,
Przemek

------------------------------------------------------------------------

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

/**
* MySQL JDBC connector test. This test causes:<br>
* <code>Exception in thread "main" java.lang.OutOfMemoryError: Java=20
heap space</code>
*
* @author Oskar Sawicki
*
*/
public class MySQLTest {

private final static String DB_NAME =3D "test";

private final static String DB_USER =3D "root";

private final static String DB_PASSWD =3D "";

private final static String TABLE_NAME =3D "test";

/**
* Main method. Makes connection and executes testing query.
*
* @param args
* @throws SQLException
* @throws ClassNotFoundException
* @throws InstantiationException
* @throws IllegalAccessException
*/
public static void main(String[] args) throws SQLException,
ClassNotFoundException, InstantiationException,
IllegalAccessException {

String driver =3D "com.mysql.jdbc.Driver";
String url =3D "jdbc:mysql://localhost/" + DB_NAME + "?user=3D" =
+=20
DB_USER
+ "&password=3D" + DB_PASSWD
+ "&useUnicode=3Dtrue&characterEncoding=3Dlatin2 ";

Class.forName(driver).newInstance();

Connection conn =3D DriverManager.getConnection(url);

String sql =3D "drop table if exists " + TABLE_NAME + ";";
Statement stmt =3D conn.createStatement();
stmt.execute(sql);

sql =3D "CREATE TABLE "
+ TABLE_NAME
+ " (col1 int, col2 varchar(255), col3 text, col4 int,=20
col5 varchar(255), col6 text, col7 int, col8 varchar(255), col9 text)";
stmt =3D conn.createStatement();
stmt.execute(sql);

for (int i =3D 0; i <=3D 200; i++) {
sql =3D "insert into "
+ TABLE_NAME
+ " values ('1','2','3','4','5','6','7','8','9')";
stmt =3D conn.createStatement();
stmt.execute(sql);
}
for (int i =3D 0; i <=3D 300; i++) {
System.out.println("iteration: 100*" + i);
System.out.flush();

for (int j =3D 0; j <=3D 100; j++) {
sql =3D "SELECT * FROM " + TABLE_NAME + ";";
stmt =3D conn.createStatement();
ResultSet rs =3D stmt.executeQuery(sql);
while (rs.next()) {
rs.getString("col1");
}
}
}

conn.close();
}
}


--=20
MySQL Java Mailing List
For list archives: http://lists.mysql.com/java
To unsubscribe: http://lists.mysql.com/java?unsub=3D...brujo (DOT) it


--
MySQL Java Mailing List
For list archives: http://lists.mysql.com/java
To unsubscribe: http://lists.mysql.com/java?unsub=3D...ie.nctu.edu.tw