Neo4j cypher unidirectional query when there are bidirectional relationships

Question

I don't think it's possible to do what I'm seeking, but I thought I'd throw it out for creative suggestions. The Unified Medical Language System (UMLS; https://uts.nlm.nih.gov/home.html) is a semantic ontology which has a variety of bidirectional relationships between nodes. For example x isa y and y inverse_isa x. The problem is there are many such names and their reverse directed relationship. Thus, in a query, it is not enough to exclude one because the listing has many possibilities, which is cumbersome and may overlook something. The problem, in other words, is can you create a directed acyclic graph query when there are relationships that will reverse the traversal. If you have a outbound relationship from node x to y, you want to ignore the inbound relationship to x from y. I'm using Neo4j 2.3.0. The UMLS, as I'm filtering the data, has ~11M nodes and 45M relationships. There are 654 relationship types and the list is dynamically growing; this is another reason for a generic solution not dependent on a specific listing in- and out-bound relationships.

Answer 1

If, in UMLS, every "inverted" relationship is paired with a corresponding "positive" relationship (i.e., they link the same 2 nodes, but go in opposite directions), then you could just omit the inverted relationship in the neo4j DB, since neo4j can navigate relationships in either direction. Would this solve your problem?

Answer 2

I am sorry I have only a very little understanding of the problem.

Please see if this is of any help. For inverted relationships, you can query for something like this. Here, b will be used for the reverse relationship.

match (n)-[a]->(m)-[b]->(n) return m;