First thanks to all of you for the hints and the detailed explanation of Craig. Peter I was not into any code in detail yet, but I have had a look on the (beta) wiki of Neo4j spatial.
Some more questions on the storage format of Neo4j: So the nodes, properties and relationships are stored in seperate files with their own id space. If I load information from the database I will probably have to hit each store. So lets say I have a large database of several gigabytes I will end up with three sequentiell reads (at best) at three different locations on the harddisk. If I store everything in three tables in the relational approach I will come to the same result in terms of data locality - if my assumption is correct. So no way to do a bounding box read from contiguous space when using all of the datastores? The next question goes to the way how OSM ways are stored. I thought the relationships connect the nodes to a way like "is-part-of". Now there are "proxy nodes" which connect the nodes to a way. How does the relationships now come into play? From some presentations I have seen that nodes have lat/lon and name information. Was that only for illustration and that information would normally be stored in the property store or how many information can be stored in a node at all? This would favor the way I can retrieve data then. Lets stay at OSM: How would I store a closed way which isn't connected to anything else? It would have no connection to the rest of the graph. How would that fit from a design perspective? For my master thesis I will have to write comparable importers for Neo4j and PostGIS. Your proposal to lower fragmentation sounds reasonable. I think I can adapt that (or any other approach that comes to my mind) in a branch and also add configuration options to the importer. Regards, Daniel -- View this message in context: http://neo4j-community-discussions.438527.n3.nabble.com/Neo4j-low-level-data-storage-tp3336483p3409162.html Sent from the Neo4j Community Discussions mailing list archive at Nabble.com. _______________________________________________ Neo4j mailing list [email protected] https://lists.neo4j.org/mailman/listinfo/user
