Bug 131011 Support running query based on report document data
Data Engine should support running a query based on data set and expression data stored in a report document. This bugzilla entry serves as a repository for design docs and notes related to this feature.
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/executor/transform/group/GroupUtil.java
* Determins whether input colum name is row id name
	 * 
	 * @param columnName
	 * @return true, it is rowid column name
	 */
	public static boolean isRowIdColumn( int columnIndex, String columnName )
	{
		return rowidIndex == columnIndex
				|| columnName.matches( "\\Q_{$TEMP_GROUP_\\E.*\\QROWID$}_\\E" );
	}
	/**
	 * Determin whether two values are in speficied interval. Please notice,
	 * such a calculation approach only applies to asc order. If desc order
	 * needs to be used too, the intervalValue must be conversed in the start.
	 * 
	 * @param startValue
	 * @param intervalValue
	 * @param currValue
	 * @param prevValue
	 * @return true in interval
	 */
	static boolean isWithinInterval( double startValue, double intervalValue,
			double currValue, double prevValue )
	{
		assert intervalValue != 0;
		boolean isSame = false;
		double curr = ( currValue - startValue ) / intervalValue;
		double prev = ( prevValue - startValue ) / intervalValue;