Bug 207564 Column sorting based on data type
Only string sorting happens when a column is selected in preview result page of DataSet Editor irrespective of type of data shown in that column. I'd like to be able to sort the data based on its datatype when a column is selected.
UI/org.eclipse.birt.report.designer.ui/src/org/eclipse/birt/report/designer/data/ui/util/DataSetProvider.java
{
	private static DataSetProvider instance = null;
	
	private transient Hashtable htColumns = new Hashtable( 10 );
	private static Hashtable htDataSourceExtensions = new Hashtable( 10 );
	private transient Hashtable sessionTable = new Hashtable( 10 );
	
	private static final char RENAME_SEPARATOR = '_';
	private static String UNNAME_PREFIX = "UNNAMED"; 
	/**
	 * @return
	 */