amplab/graphx — pull request #102 by ankurdave (2013-12-15 23:28:08+00:00)
Title: Add clustered index on edges by source vertex

**Depends on #100. Incremental diff: https://github.com/ankurdave/graphx/compare/mrTriplets-active-set...clustered-edge-index**

This allows efficient edge scan in mapReduceTriplets when many source vertices are inactive. The scan method switches from edge scan to clustered index scan when less than 80% of source vertices are active.