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Questions tagged [graph-databases]

A graph database uses graph structures with nodes, edges, and properties to represent and store information.

A graph database stores nodes and relationships instead of tables, or documents. Data is stored just like you might sketch ideas on a whiteboard. Your data is stored without restricting it to a pre-defined model, allowing a very flexible way of thinking about and using it.

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2926 questions
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neo4j.rb check relation already exists between two nodes

I Need to check relation between two nodes exists already. brian.following << chris brian.following #=> chris I Need to check like this brian.following?(chris) #=> true brian.following?(john) #=> false Any method is there in neo4j.rb for this? if…
Raj Adroit
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ArangoDB REST Traversal return invalid startVertex

I've been trying to do some simple traversal in python using the REST API: import requests url = "http://localhost:8529/_api/traversal" d = { "startVertex": 'V/62824208658', "graphName" : "G", "direction" : "outbound"} r = requests.post(url, data =…
tariqdaouda
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Difference between Graph Triples and EAV

Recently I've started to play with cayley and ArangoDB for their graph datastores. While reading and watching videos about graph databases a question popped up into my mind: what makes a graph database so different (and "awesome") from a typical…
Alix Axel
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Gremlin simplePath() not working in a loop

I'm trying to write a DAG traversal accounting for the possibility that the there actually might be cycles (bad data, etc.). So on the toy graph: gg = TinkerGraphFactory.createTinkerGraph() gg.v(2).addEdge('knows',…
StasM
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Timeouts on traversing from node with millions of edges

I have a graph that has some nodes with millions of incident edges, using Titan 0.5.2 on top of Cassandra DB. E.g. this reproduces such graph: mgmt = g.getManagementSystem() vidp =…
StasM
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Neo4j 2.1.6 Hello World in NetBeans maven project

My configuration is : * OS : Windows 8 * Neo4j community 2.1.6 (latest stable) * IDE : NetBeans 8.0.2 (latest) * java -version java version "1.8.0_25" Java(TM) SE Runtime Environment (build 1.8.0_25-b18) Java HotSpot(TM) 64-Bit Server VM (build…
ARMBouhali
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Which database to use for highly-connected data model with frequent schema changes?

I am currently working on a project, where we use web mining (web crawlers) to build up a company database. At the moment we employ PostgreSQL as our main database, however, I feel it will cause a lot of problems in the future, because as our…
Erik
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Return one result per person in neo4j

Assuming I have this graph in neo4j: CREATE (a:Person {name: "Person A"}) CREATE (b:Person {name: "Person B"}) CREATE (r1:TestA {result: 1}) CREATE (r2:TestA {result: 2}) CREATE (r3:TestA {result: 3}) CREATE (r4:TestA {result: 3}) CREATE…
Sebastian
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How can I use cypher query to return the count of all the elements in one array?

How can I count all the elements in one array with Neo4j cypher query? For example, if I have a relationship like (a)-[:REL{type:[‘A’,’B’]}]->(b) What’s the cypher query that I need to obtain the count of the elements of the attribute type? I…
davide.ferrari
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Cypher Relationship Type returning no results

I'm getting some unexpected results when trying to define the type of a relationship in a Cypher Query. My model consists of Action nodes which are related to an ActionType node via an :OCCURRENCE_OF relationship. Here is a sample create…
user3132965
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Update property value in Neo4j on import

I have the following code for importing data in CSV. The data is of the form A-[:LIKES {times: x}]-B where x is a number. However when importing, I am stuck on how to update the value of times if the relationship is found again. There seems to be a…
GvanJoic
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How to add infinity, NaN, or null values to a double[] property on a node in Cypher/Neo4j

I have some nodes in my neo4j graph that are a combination of multiple entities. On these nodes I have a property named "p_value" that has a type of double[]. I'm merging new entities into existing nodes and with my merge command I'm using on match…
AFK
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How to use @rid in OrientDB?

I'm new to OrientDB. I would like to use the functionalities of OrientDB, however, my mind is a little bit confused with the usage of @rid function. I have read the web documentation of the application and group discussions, and I am trying to…
Yilmazerhakan
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Embedded neo4j server and web admin at the same time

I followed the instructions at the following links, however, when I run my program and go to http://localhost:7474/ the webpage of the web admin is not available. How to connect to a locally installed neo4j server using Java Neo4j Hello World…
user2360448
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How to decide whether to create a node or a property in Neo4j

I'm having few Nodes. lets say User 1,User 2,User 3. if i want to mention the college of users, which of the following approach gives us better performance. 1: Creating College as node (or) 2: just keeping college name as property in…
Pavan Kumar Varma
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