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From Avery Ching <ach...@apache.org>
Subject Re: Primitives vs Objects (the Movie!)
Date Thu, 08 Sep 2011 01:09:55 GMT
On 9/7/11 3:49 PM, Jake Mannix wrote:
> On Wed, Sep 7, 2011 at 10:43 PM, Dmitriy Ryaboy <dmitriy@twitter.com 
> <mailto:dmitriy@twitter.com>> wrote:
>
>     Something else to think about -- in some cases you may want to
>     implement extreme compression of the edge list. For example, we might
>     want to calculate n-th degree reach for all nodes in a graph. Given a
>     graph with a few nodes with lots of incoming edges ("biebernodes", we
>     call them), anything that jumps across them winds up essentially
>     replicating large chunks of the graph to each node. Things like RLE
>     might make sense when you are doing that sort of thing in memory and
>     only have so many terabytes of that lying around.
>
>
> Right, in some cases, we may want to not have edge values at all.  Just
> existence in the vertex's target list of a target vertex id denotes 
> "connection",
> and so "SortedMap<I, Edge<E,I>>" gets replaced with "long[]".
>   -jake
In this type of case, you could also use the vertex value to store a 
application specific set of edges and edge values (if any).

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