Has anyone implemented a path finding algorithm (A*, Dijkstra's algoritm, Breath First Search, etc.) using CouchDB's maps & views? Is it even possible? I've seen some implementations for other mapreduce software (e.g. http://horicky.blogspot.com/2010/02/nosql-graphdb.html), however they rely on an global state, which CouchDB lacks (right?). Is it even possible to do a graph traversal algorithm within the confines of CouchDB?
Let's assume you have complete control over the input document format.