And now it's ready.
If you are using SNAPSHOT, please update your dependencies, and check it
out.
http://docs.neo4j.org/chunked/snapshot/query-start.html#start-relationship-by-index-lookup
Thanks again for providing feedback. It's much more fun coding when I know
someone is using it.
Andrés
On Fri, Sep 30, 2011 at 10:37 AM, Andres Taylor <
andres.tay...@neotechnology.com> wrote:
> Hey!
>
> This is something that has been planned since the very first iteration of
> Cypher, but no-one seemed to need it, so I have pushed it in front of me.
>
> Now we seem to have an user that wants it, so I'll add it.
>
> Don't hold your breath though - it'll be ready when it's ready.
>
> Andrés
>
>
> On Thu, Sep 29, 2011 at 1:10 PM, st.pa <st...@web.de> wrote:
>
>> hi.
>> when i use a cypher query to get the queued nodes associated via
>> queue-relationships to a repository-node which has several million other
>> relationships then it takes about six minutes to fill that result list:
>>
>> <pre>
>> List<Node> list = new ArrayList<Node>();
>> StringBuffer s = new StringBuffer();
>> s.append("START repository = (");
>> s.append((Long) controller.getRepositoryNode().getId());
>> s.append(") MATCH (repository)-[:");
>> s.append(Rels.REL_REPOSITORY_QUEUE);
>> s.append("]->(node) RETURN node ORDER BY node.");
>> s.append(Keys.KEY_TIMESTAMP);
>> s.append(" SKIP ");
>> s.append(Integer.toString(offset));
>> s.append(" LIMIT ");
>> s.append(Integer.toString(buffersize));
>> Log.log(s.toString());
>> Query query = this.parser.parse(s.toString());
>> ExecutionResult result = this.engine.execute(query);
>> Iterator<Node> iterator = result.columnAs("node");
>> while (iterator.hasNext()) {
>> list.add(iterator.next());
>> }
>> </pre>
>>
>> but when i directly query the relationshipIndex containing all
>> queue-relationships and assuming that sorting by timestamp is equivalent
>> to sorting by node-ids then it completes in just half a minute, which is
>> a dozen times faster:
>>
>> <pre>
>> List<Node> list = new ArrayList<Node>();
>> IndexHits<Relationship> hits =
>> controller.getRelationIndexRepositoryUrlQueue().query(
>> Keys.KEY_TYPE,Rels.REL_REPOSITORY_QUEUE,
>> controller.getRepositoryNode(),null
>> );
>> List<Long> ids = new ArrayList<Long>();
>> try {
>> for (Relationship hit : hits) {
>> ids.add(
>> hit.getEndNode().getId()
>> );
>> }
>> } finally {
>> hits.close();
>> }
>> Collections.sort(ids);
>> for (int i = offset; i < Math.min(offset + buffersize,ids.size()); i++) {
>> list.add(
>> this.graph.getNodeById(
>> ids.get(i)
>> )
>> );
>> }
>> </pre>
>>
>> now my question. how can i efficiently get such a result list sorted for
>> some node property other than id. and question number two: how would a
>> cypher statement look like if it supported relationship-indices. maybe
>>
>> <pre>
>> START x = (1)
>> MATCH (x)-[r:(MyRelationIndex,type,MyRelationType)]->(y)
>> RETURN r,y
>> ORDER BY y.somePropertyOtherThanId
>> </pre>
>>
>> similar to nodeIndexLookups, where i give the name of the relationship
>> index to use, key and value for the relationship, start and end nodes
>> are given by (x) and (y) in this case. i'd like that feature very much
>> and if i knew how i'd probably even help to get on with it but anyway i
>> can be patient.
>>
>>
>> kindly, st.p.
>> _______________________________________________
>> Neo4j mailing list
>> User@lists.neo4j.org
>> https://lists.neo4j.org/mailman/listinfo/user
>>
>
>
_______________________________________________
Neo4j mailing list
User@lists.neo4j.org
https://lists.neo4j.org/mailman/listinfo/user
