CODEWITHSUNDEEP
javagraphgremlinjanusgraph
Huds0nHawk
Huds0nHawk

Reputation: 1496

Gremlin: Find all downstream (out) paths from given Vertex

I have a directed graph with around 1000 vertices and 3000 edges that contains cycles.

I am trying to find all downstream (out) paths from given Vertex.

When using following Gremlin query

g.V(45712).repeat(out().simplePath()).until(outE().count().is(0)).path()

For some paths it takes forever to get the result because of the cycles, although the simplePath step should prevent this.

I tried to optimize the query and not go over the same Vertex twice using aggregate step and without, but now some Vertices are being skipped.

g.V(45712).repeat(out().where(without('x'))
.aggregate(Scope.local,'x'))
.until(outE().count().is(0))
.path()

Thanks

Upvotes: 1

Views: 744

Answers (1)

Kelvin Lawrence
Kelvin Lawrence

Reputation: 14391

If your data is highly connected, that can be an expensive query. Even with a small graph. I have seen people use constraints to try and restrict the total amount of searching. These could include using times or loops to set a maximum search depth. Even with my air-routes data set, which is really quite a small graph, that query could yield a very large result set. It's not so much that your Gremlin is wrong. It's more going to depend on how connected the vertices are.

Searching for all paths from a given start in general is likely to be expensive query.

Upvotes: 2

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