neo4j
An active model wrapper for the Neo4j Graph Database for Ruby.
Neo4j.rb: (ruby)-[:LOVES]-(neo4j)
Hi I created a neo4j database with custom java application and tried to change path in configuration file in order to connect to created database.
While trying to check the data in webadmin console only node 0 is visible (seems that the database is empty). I tried to import the same database to Gephi and it's not empty.
Furthermore when I tried to switch back to the original database, which also wasn't empty, in webadmin only node 0 appeared.
I tried to modify the neo4j-server.propertied file the following way:
#*****************************************************************
# Administration client configuration
#*****************************************************************
# location of the servers round-robin database directory. possible values:
# - absolute path like /var/rrd
# - path relative to the server working directory like data/rrd
# - commented out, will default to the database data directory.
org.neo4j.server.webadmin.rrdb.location=data/rrd
# REST endpoint for the data API
# Note the / in the end is mandatory
#org.neo4j.server.webadmin.data.uri=/db/data/ #original database
org.neo4j.server.webadmin.data.uri="/db/mydatabase" #my database
# REST endpoint of the administration API (used by Webadmin)
org.neo4j.server.webadmin.management.uri=/db/manage/
# Low-level graph engine tuning file
org.neo4j.server.db.tuning.properties=conf/neo4j.properties
After switching back to the original database (commenting the new path and uncommenting the old)
org.neo4j.server.webadmin.data.uri=/db/data/ #original database
#org.neo4j.server.webadmin.data.uri="/db/mydatabase" #my database
the old wan seemed to be empty as well.
Does anyone know how and where to set path in order to see the appropriate database in webadmin console and be able to execute queries on the desired database?
Thank you!
Source: (StackOverflow)
This is a somewhat abstract and general question. I'm interested in the inherent (as well as implementation-specific) properties of different approaches to persist unstructured data with both lots of internal references (graph-like) and lots of properties (JSON-like).
Since a graph is a superset of a tree, you can look at graph DBs (e.g. Neo4j) as a superset of document DBs (e.g. MongoDB). That is, a graph DB provides all the functionality of a document DB plus additionally also allows loops or has a native pointer type so you don't have to dereference foreign-keys/ids manually.
So is there some tipping point that you reach when adding more references to your objects/resources where you're better off with a graph DB but were previously better off with a document store? Are there advantages to document DBs (storage space, performance?) or should you just always go with a graph DB just in case you'll need more references in the future?
Similarly, how do graph DBs and triplestores (e.g. RDF stores) compare? Graph DBs (where nodes and edges have properties) seem to be a superset of the simple triplestores. So for what problems (if any) perform triplestores actually better then, say Neo4j? (One advantage of RDF stores is that there is a standardized query language – SPARQL – although there seem to be a lot of people that don't like SPARQL and thus would call it a disadvantage.)
I guess my question is: The graph model (with properties) seems to be able to neatly express all kinds of data, what is the catch when you enter reality? I suppose the catch of graph DBs is performance, so I'd love to see some numbers or rules of thumb on what kind of slowdowns to expect when loading, querying and modifying data as well as memory, and persistent storage requirements (compared to document and triple stores). Also what about horizontal scalability? I got the impression that there the playing field is quite level.
Do you think it is possible that graphs with their expressibility will become the new default storage model for projects that have not super-large data, or are we doomed for a decade of Polyglot Persistence with RDBMS, JSON stores and Graph DBs living along each other that have to be integrated with even more glue code?
Source: (StackOverflow)
have a question on graph databases, can some one help me please? I'm
handling quite a lot of data in mysql about 5M records a day sent by a
router like device, access points, wireless bridges. The data is
usually health data, gps etc... these are devices on vehicles. How do
you handle time based data in graph databases? Has anyone applied
neo4j for time-based data? It would be great to know how you query
intervals and how you'd go about modelling.
I guess I can create a node for every single time i receive data with
properties set each time like changed gps, health? It would be a time
based graph - does that sound right?
well with 5M rows mysql isn't performing bad - but as router gets new
functionality new data comes through and I need to create new models
again which isn't bad but not great.
i want something which is semi structured and makes relating different
things like why the user got kicked out is because of an access point
associated to the router is down. My usual queries would be to raise
alerts to say one of the device is down or if there is a reduced
throughput etc. Would neo4j help me in marrying up these relationships
better than mysql?
Would love to know what you guys think, any comments + thoughts
appreciated.
Source: (StackOverflow)
How to delete labels in neo4j? Actually I deleted all nodes and relationships, then I recreated the movie database and still the labels I created before appeared on the webinterface. I also tried to use a different location for the database and even after an uninstall and reinstall the labels still appeared. Why? Where are the labels stored? After the uninstall the programm, the database folder and the appdata folder were deleted.
How to reproduce? Install neo4j -> use the movie database example -> create (l:SomeLabel {name:"A freaky label"}) -> delete the node -> stop neo, create new folder -> start neo -> create movie shema -> match (n) return (n) -> SomeLabel appears, even if you changed the folder or make an uninstall / install.
Is there a way to delete labels even if there is no node with it?
Source: (StackOverflow)
How can i inject a properties file containing a Map to be used as additional constructor arg using the field.
With a Map being loaded from a properties file
the bean is currently setup using:
<bean id="graphDbService" class="org.neo4j.kernel.EmbeddedGraphDatabase"
init-method="enableRemoteShell" destroy-method="shutdown">
<constructor-arg index="0" value= "data/neo4j-db"/>
<constructor-arg index="1" value=? />
</bean>
Java Equivalent:
Map<String,String> configuration = EmbeddedGraphDatabase.loadConfigurations( "neo4j_config.props" );
GraphDatabaseService graphDb = new EmbeddedGraphDatabase( "data/neo4j-db", configuration );
Thanks
Source: (StackOverflow)
I'm starting to develop with Neo4j using the REST API.
I saw that there are two options for performing complex queries - Cypher (Neo4j's query language) and Gremlin (the general purpose graph query/traversal language).
Here's what I want to know - is there any query or operation that can be done by using Gremlin and can't be done with Cypher? or vice versa?
Cypher seems much more clear to me than Gremlin, and in general it seems that the guys in Neo4j are going with Cypher.
But - if Cypher is limited compared to Gremlin - I would really like to know that in advance.
Source: (StackOverflow)
I am wondering what the best ways to store graphs in persistent storage are, for later analysis, search, clustering, etc.
I see neo4j being an option, I am curious if there are also other graph databases available. Does anyone have any insights into how larger social networks store their graph based data (or other sites that require the storage of graph like models, e.g. RDF).
What about options like Cassandra, or MySQL?
Source: (StackOverflow)
Can anybody please provide or point out to a good comparison between Neo4j and Titan?
One thing i can see is in terms of scale - Titan is scaleout and requires an underlying scalable datastore like cassandra. Neo4j is only for HA and has its own embedded database. Any other pros and cons? Any specific usecases. (Is Titan being used anywhere currently?)
I also have the following link: http://architects.dzone.com/articles/16-graph-databases-compared that gives a objective compare for graph databases but not much on pros and cons between Neo4j and Titan.
Source: (StackOverflow)
I am looking at integrating Neo4j into a Clojure system I am building. The first question I was asked was why I didn't use Datomic. Does anyone have a good answer for this? I have heard of and seen videos on Datomic, but I don't know enough about Graph Databases to know the difference between Neo4j and Datomic, and what difference it would make to me?
Source: (StackOverflow)
Is there a .NET version/binding for Neo4j?
It looks like exactly what I want, but I'm working in C# on .NET.
Thanks
Source: (StackOverflow)
It appears that LIKE is not supported in Cypher queries.
Is there any other construct that would perform the same task?
For instance:
start n = node(*) where n.Name LIKE('%SUBSTRING%') return n.Name, n;
Source: (StackOverflow)
How can I kill a currently long-running query in Neo4j (without restarting the server)?
I know we can globally set a timeout for queries, but sometimes I want to execute heavy queries/creates/updates on the server that could take a while...
Thanks.
Source: (StackOverflow)