public class Table {

    private String tableName;
    private String[] columnNames;
    private int[][] rows;
    private static Hashtable tables = new Hashtable();

    public static Table byName(String tableName) {

    public Table project(String[] colNames) throws Exception {

    public Table select(String colName, Op op, int value) 
        throws Exception {

    public Table join(String selfColName, Table otherTable, 
                      String otherColName)
        throws Exception {

}