Updating a node creates new RTREE_REFERENCE relationship

[Alex-Wauters]

The nodes in our geospatial index can change location (frequently). At the moment, we modify the properties in the node and add it to the index anew by posting to:

/db/data/ext/SpatialPlugin/graphdb/addNodeToLayer

with

{"layer": "geom", "node", "nodeID"}

Which updates the bounding boxes of the geospatial index, but creates a new RTREE_REFERENCE relationship. Is there a way to update the geospatial location of a node, without creating a new relationship after each update operation?

Alternatively we can create a batch job which reduces X references (X > 1) to 1; or delete the first reference in the same transaction, but preferably we would like to avoid it.

[ehx-v1]

from what I get, frequently moving things are not supposed to be modeled as geospatial nodes... I mean, you wouldn't call a cow a geospatial landmark, would you? (not meant to offend anyone, just making an example, same with cars and stuff) or, hang on... are you implementing a Sims City-styled virtual building reality with Spatial? that would be an interesting use case the creators certainly haven't thought of! I'd add a "like" to this idea!

[Alex-Wauters]

Sorry to disappoint you, we are not implementing a Sims City-styled virtual building reality. We have neo4j entities with location properties, and would like to use the Neo4j Spatial library for Geospatial operations on Neo4j entities, to perform a geospatial operation (withinDistance) on these entities.

[ehx-v1]

so it's kind of how far cars are away from each other?

[Alex-Wauters]

Correct, from a certain location. In case anyone is interested, our current approach cleans up the database at regular moments with the following commands:

Clean double relationships

match s-[r:RTREE_REFERENCE]->e 
with s,e,type(r) as typ, tail(collect(r)) as coll 
foreach(x in coll | delete x)

Clean empty bounding boxes:

match (x)-[r:RTREE_CHILD]->(n)
WHERE NOT (n)-[]->()
delete r,n

The latter query would be cleaner if the bounding box nodes had a label, like the RTREE metadata node.