hibernating-rhinos/rhino-etl — pull request #10 by jonmpqts (2013-09-18 18:10:33+00:00)
Title: Added an aggregation operation that assumes a sorted rowset.

For cases in which we know the rows have been sorted in advance, this operation yield returns the current aggregate as soon as a change in keys is detected. This avoids having to load aggregate all rows before returning.