Bug 123915 Add table-fetch limitation when DataSet Editor is populating table names.
When fetch table names from database of large volume of data, there lies a possibility that the editor window will be frozen because of the population of huge number of table names. This should be enhanced. A handy solution might be limiting the number of table names being fetched each schema.
data/org.eclipse.birt.report.data.oda.jdbc.ui/src/org/eclipse/birt/report/data/oda/jdbc/ui/editors/SQLDataSetEditorPage.java
/**
	 * populate shema list if the schema is supported
	 *
	 */
	protected void populateSchemaList()
	{
		if ( rootNode != null )
		{
			removeTreeItem( rootNode );
		}
		getAvailableSchema();
		
		if ( schemaCombo.getItemCount() < 1)
		{
			schemaCombo.add( JdbcPlugin.getResourceString("tablepage.text.All") );
			schemaCombo.select( 0 );
			if( schemaList != null){
				Iterator it = schemaList.iterator( );
				while ( it.hasNext( ) )
					schemaCombo.add( it.next( ).toString( ) );
			}
		}
		ArrayList targetSchemaList = new ArrayList();	
		ArrayList schemaObjectList = new ArrayList();
		if(schemaList!=null)
		{
			int numberOfSchema = 0;
			Preferences preferences = ReportPlugin.getDefault( )
					.getPluginPreferences( );
			if ( preferences.contains( DateSetPreferencePage.USER_MAX_NUM_OF_SCHEMA ) )