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/GroupCalculationUtil.java
}
	/**
	 * Sort data rows by group information and sort specification
	 * 
	 * @throws DataException
	 */
	public SortSpec getSortSpec( ) throws DataException
	{
		assert groupDefs != null;
		
		
		int groupCount = 0;
		int sortCount = 0;
		for ( int i = 0; i < groupDefs.length; i++ )
		{
			
			
			if ( groupDefs[i].getColumnIndex( ) >= 0 )
			{
				groupCount++;
			}
		}
		if ( query.getOrdering( ) != null )
		{
			sortCount = query.getOrdering( ).length;
		}
		int[] sortKeyIndexes = new int[groupCount + sortCount];
		String[] sortKeyColumns = new String[groupCount + sortCount];
		boolean[] sortAscending = new boolean[groupCount + sortCount];
		for ( int i = 0; i < groupCount; i++ )