Daniel, of course you could use native external indicies instead of in-graph structures, but then you loose much of the topology capabilities of a connected graph. However, probably it's a good idea to provide some example of that, too. Got a link to a good native RTree implementation that could be used?
Cheers, /peter neubauer GTalk: neubauer.peter Skype peter.neubauer Phone +46 704 106975 LinkedIn http://www.linkedin.com/in/neubauer Twitter http://twitter.com/peterneubauer http://www.neo4j.org - Your high performance graph database. http://startupbootcamp.org/ - Öresund - Innovation happens HERE. http://www.thoughtmade.com - Scandinavia's coolest Bring-a-Thing party. On Mon, Oct 10, 2011 at 11:56 AM, danielb <danielbercht...@gmail.com> wrote: > Retrieving data in constant time sounds very promising especially for routing > purposes. Did you allready have thoughts on algorithms that use hierarchies > or contraction of the network? In our students project we implemented some > approaches to reduce search space and have thoughts on the heuristics used > for A*. When travel speed comes into concern we got very different results > with SLD heuristics. Maybe this could be of interest for Neo4j. > When doing bounding box queries the only advantage of Neo4j could be better > spatial locality of data ('nodes' and 'ways' both stored in the same > container). Everything else is up to the r-tree performance as in PostGIS, > which uses an improved r-tree in GIST. Maybe you can do an r-tree search for > the first node near the center of the bounding box and with some magic > retrieve the surrounding nodes with graph traversing... At least I will > think about this, if you can improve bounding box queries over PostGIS. > When I switch to a low zoomlevel I want to use generalization and > simplification of mapdata. In Neo4j I can model that within subgraphs I > guess? For example have different relationships for different zoomlevels (I > skip some nodes of a way for example). I could also build a routing network > within subgraphs where I skip non-junction nodes for example? > Btw what do you think from building a graph inside a relational database? As > I understand now it would be very inefficient because you would have at > least two tables (vertices and edges) and have to do time demanding joins > with the two foreign key colums in the edge table. > > Regards, Daniel > > > -- > View this message in context: > http://neo4j-community-discussions.438527.n3.nabble.com/Neo4j-in-GIS-Applications-tp3393925p3409062.html > Sent from the Neo4j Community Discussions mailing list archive at Nabble.com. > _______________________________________________ > Neo4j mailing list > User@lists.neo4j.org > https://lists.neo4j.org/mailman/listinfo/user > _______________________________________________ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
