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
return type;
	}
	/**
	* @param item A tree Item which has to be tested
	* @return if the TreeItem represents a Schema node
	*/
	protected boolean isSchemaNode( TreeItem item )
	{
		if ( item != null && isSchemaSupported )
		{
			if (item.getParentItem() == rootNode)
			{
				return true;
			}
		}
		return false;
	}
	
	private void refreshPage() 
	{
		
		OdaDataSourceHandle curDataSourceHandle = (OdaDataSourceHandle) ((OdaDataSetHandle) getContainer( ).getModel( )).getDataSource();
		
		if( curDataSourceHandle != prevDataSourceHandle )
		{
			RemoveAllAvailableDbObjects();
			resetJdbcInfo(curDataSourceHandle);
			enableSchemaComponent( isSchemaSupported );
			setRootElement();