You shouldn't remove information from your query, if need be anonymize it or adapt it. Otherwise you can't get real help.
What is the actual use-case you want to solve? What do you actually want to do? The query you had will do a full graph scan, not something you want to do. Make sure to use graph queries (i.e. ones that actually traverse relationships). The query you have pulls all data in your database from disk and pushes it through a Cypher query (i.e. 600M elements), certainly not a real use-case. If you split your union into two queries, how long is the runtime of each of the queries? for the second one I'd probably go with start r=rels(*) WHERE ... On Sun, May 18, 2014 at 6:12 AM, gfourhsean Ionessa < [email protected]> wrote: > Hello Neo4j Guru's, > > I know this question has been asked already in previous posts (which I > have read) but I feel like something else is causing my issue maybe. > > To lay out as much as I can, I have been assigned to manage a database > based off of Neo4j version 2.0.0 with a database size of ~250 Gigabytes. > The problem my team has been encountering is ridiculously slow database > querying (from 30 minutes to an hour before receiving results). The queries > are executed using the web front end on the webadmin page. Below are the > details for the graph nodes and relationship details to get an ideal of the > size of the database I am dealing with. I am wondering if the sheer size of > the database is the cause for such a slow query performance or is there > something else that may be going on which I must look into. > > Test Query (With actual label information removed for privacy reasons): > > MATCH (n) WHERE has(n.`person`) RETURN DISTINCT "node" as element, > n.`person` AS `person` LIMIT 25 UNION ALL MATCH ()-[r]-() WHERE > has(r.`person`) RETURN DISTINCT "relationship" AS element, r.`person` AS > `person` LIMIT 25 > > *The server Configuration:* > > CPU's: 24x E5-2630 2.30 GHz > Memory: 125 Gigabytes of DDR3 > Hard disk: 5 Terrabytes > > *JVM Settings manually set (in neo4j-wrapper.conf):* > > # Initial Java Heap Size (in MB) > wrapper.java.initmemory=16 > > # Maximum Java Heap Size (in MB) > wrapper.java.maxmemory=32768 > > *Linux system settings manually set:* > > ulimit set to 40000 > > under /etc/sysctl.conf: > vm.dirty_background_ratio = 50 > vm.dirty_ratio = 80 > > *Node and relation information:* > > "description": "Estimates of the numbers of different kinds of Neo4j > primitives", > "description": "An estimation of the number of nodes used in this > Neo4j instance", > "name": "NumberOfNodeIdsInUse", > "value": 255857300, > > "description": "An estimation of the number of relationships used in > this Neo4j instance", > "name": "NumberOfRelationshipIdsInUse", > "value": 375613862, > > "description": "An estimation of the number of properties used in > this Neo4j instance", > "name": "NumberOfPropertyIdsInUse", > "value": 1518707868, > > > "description": "The number of relationship types used in this Neo4j > instance", > "name": "NumberOfRelationshipTypeIdsInUse", > "value": 8, > > > I want to apologize in advance for my lack of knowledge of Neo4j but I am > willing to learn as much as I can to fix this issue. > > Sincerely, > JP > > -- > You received this message because you are subscribed to the Google Groups > "Neo4j" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Neo4j" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
