Hi guys,
with my colleagues we are comparing two graph databases wich one is neo4j.
We have around 100k of nodes and 1m of edges and we need traverse the graph
by a start node.
While in other db we have no difficult to get the results in few seconds,
in neo4j we get several performance issue.
Our problem:
Given a start node are considered valid all paths that satisfy a condition:
Given a range [1, 10]
if a edge "r" has r.property in [1,10] and r.property = x the next edge
"r1", of the path, must have r1.property in [x,10] and so on...
For small ranges the performance of two dbs are comparable...
We use the traversal api:
private Traverser getFoF(final Node node, boolean isBackward,
Long start, Long end) {
TraversalDescription td = graphDb
.traversalDescription()
.order(BranchOrderingPolicies.PREORDER_DEPTH_FIRST)
.relationships(RelTypes.MOVES, Direction.OUTGOING)
.evaluator(Evaluators.excludeStartPosition())
.uniqueness(Uniqueness.RELATIONSHIP_PATH)
.evaluator(new PathFilter(start, end));
return td.traverse(node);
}
public class PathFilter implements Evaluator, Predicate {
Long lastValue = 0L
, start = 0L
, end = 0L;
public PathFilter(Long start, Long end) {
this.start = start;
this.end = end;
}
@SuppressWarnings("unchecked")
public Evaluation evaluate(Path path) {
List<Relationship> filteredRels = (List<Relationship>)
CollectionUtils.select(IteratorUtils.toList(path.relationships().iterator()),
new PathFilter(start, end));
if (path.length() == filteredRels.size()) {
return Evaluation.INCLUDE_AND_CONTINUE;
}
return Evaluation.EXCLUDE_AND_PRUNE;
}
public boolean evaluate(Object arg) {
if (!(arg instanceof Relationship)) {
return false;
}
if (lastValue == 0L) {
lastValue = start;
}
Relationship rel = (Relationship) arg;
Long property = (Long) rel.getProperty("property");
if (evaluateDate(property, lastValue, end)) {
lastValue = property;
return true;
}
return false;
}
private boolean evaluateDate(Long value, Long start, Long end) {
return value >= start && value <= end;
}
}
Another request:
exists already a construct that allows cypher to make an assessment of this
type?
Thanks to all
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