Bug 146967 Total fuction with result of the aggregate on group-Level should be enhanced
Description: Now if we want to do total fuction with the Aggregate result on the group level, it cant be fulfilled. For example, we set a total.sum() aggregate on a group level first, and then we sum the result of total.sum() again. The expected result should simply equal to sum over all rows. But the actual result is not as our requirement. I attached the design file as the example. Expected result: The aggregation on the group total should be enhanced, or we cant get expected result such as the requirement that total.rank() with the average result on the group level and so on.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/i18n/ResourceConstants.java
{
	public final static String UNDEFINED_DATA_SOURCE = "data.engine.UndefinedDataSource";
	public final static String UNDEFINED_DATA_SET = "data.engine.UndefinedDataSet";
	public final static String UNSUPPORTED_DATASOURCE_TYPE = "data.engine.UnsupportedDataSourceType";
	public final static String UNSUPPORTED_DATASET_TYPE = "data.engine.UnsupportedDataSetType";
	public final static String UNSUPPORTED_GROUP_ON_BLOBAndCLOB ="data.engine.UnsupportedGroupOnClobAndBLOB";
	public final static String UNSUPPORTED_SORT_ON_BLOBAndCLOB ="data.engine.UnsupportedSortOnClobAndBLOB";
	public final static String UNSUPPORTED_DIRECT_NESTED_AGGREGATE="data.engine.UnsupportedDirectNestedAggregate";
	public final static String NOT_END_GROUP  = "data.engine.EndOfGroupOnly";
	public final static String INVALID_AGGR_GROUP_LEVEL  = "data.engine.InvalidAggrGroup";
	public final static String INVALID_AGGR_PARAMETER  = "data.engine.WrongNumAggrArgs";
	public final static String INVALID_AGGR_GROUP_EXPRESSION ="data.engine.InvalidAggrGroupExpression";
	public final static String DUPLICATE_PROPERTY_NAME = "data.engine.DupPropertyName";
	public final static String SUBQUERY_NOT_FOUND = "data.engine.NoSubQueryName";
	public final static String MISSING_DATASOURCE_EXT_ID = "data.engine.DataSourceMissingExtId";
	public final static String STARTING_GROUP_VALUE_CANNOT_BE_NULL = "data.engine.NullGroupStart";
	
	public final static String RESULT_CLOSED = "data.engine.ResultClosed";
	public final static String NO_CURRENT_ROW = "data.engine.NoCurrentRow";
	public final static String INVALID_JS_EXPR = "data.engine.InvalidJSExpr";
	public final static String INVALID_TOTAL_NAME = "data.engine.InvalidTotalFuncName";