neo4j

问题 I understand that explicit configuration of mapped memory, cache and heap is necessary when running Neo4j with large graphs. Please provide me with some pointers on how can I change these settings? I realise you need to test with different settings, but what is a good starting point? Neo4j Community version: 2.2RC01 Java Embedded database Machine: 8GB RAM Graph size: 20M nodes(5 properties), 220M edges(2 properties) 回答1: See the manual for the config, for RC01 you only have to set the page

问题 When I've created some constraints on the graph, how is possible to see them and in case eliminate them? What is the syntax to treat them as elements of the graph? 回答1: In the neo4j browser you can use the :schema command to list them. In shell it is schema Then you can remove them with `DROP INDEX ON :Label(prop)` or `DROP CONSTRAINT ON (n:Label) ASSERT n.props IS UNIQUE` 回答2: In Browser you can use CALL db.constraints to get all constraints on graph. For more Info: https://neo4j.com/docs

问题 I am wondering how to use Neo4j to find the MST? Most examplesI found was using Hadoop to find it. 回答1: I don't think that this is possible in Cypher, given how current algorithms determine an MST (if I'm wrong on this, I'd love to know). Instead, I'd recommend implementing one of the algorithms used for determining an MST, e.g. Prim's Algorithm. It's quite straight forward and, with the help of heaps and adjacency lists, is relatively performant. A quick search for the algorithm will turn up

问题 I have read this article. It states, that Neo4j can scale horizontally, but only to increase read performance and fault tolerance... so the stored graph is copied to each server in a cluster. But what if I have a dataset that is larger than one server can store? Does Neo4j fail in this situation? Do I have to scale vertically in this situation and buy larger HDD? Thank you 回答1: Yes. You need enough hard drive space to contain the full graph on all nodes of the cluster, no way around that. If

问题 I was wondering if there are any advantages or disadvantages in storing data into relationships or nodes. For example, if I were to store comments related to a discussion into the DB, should I store the comment data in a "comment" relationship or a "comment" node that is related to the discussion through a separate relationship. 回答1: The correct data model depends on the types of queries you need to make. You should figure out what your queries are, and then determine a data model that meets

问题 I was wondering if there are any advantages or disadvantages in storing data into relationships or nodes. For example, if I were to store comments related to a discussion into the DB, should I store the comment data in a "comment" relationship or a "comment" node that is related to the discussion through a separate relationship. 回答1: The correct data model depends on the types of queries you need to make. You should figure out what your queries are, and then determine a data model that meets

问题 I was wondering if there are any advantages or disadvantages in storing data into relationships or nodes. For example, if I were to store comments related to a discussion into the DB, should I store the comment data in a "comment" relationship or a "comment" node that is related to the discussion through a separate relationship. 回答1: The correct data model depends on the types of queries you need to make. You should figure out what your queries are, and then determine a data model that meets

问题 I am working on a project where I am using Spark for Data processing. My data is now processed and I need to load the data into Neo4j . After loading into Neo4j, I will be using that to showcase the results. I wanted all the implementation to de done in Python Programming. But I could't find any library or example on net. Can you please help with links or the libraries or any example. My RDD is a PairedRDD. And in every tuple, I have to create a relationship. PairedRDD Key Value Jack [a,b,c]

问题 I have a data set in csv format. One of the fields is a type, like an enumeration. Based on this type I need to create different types nodes and relations when loading the data using csv load. You could call a row in the csv for a super type having an attribute defining its subtype. I'm not really able to figure out how this can be done in cypher. Is my only option to split the one csv file into a csv file per type and run different cyphers ? 回答1: This document on conditional statements helps

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 5 years ago . I am playing with neo4j to store some data with JAVA. I would like to have a good way to visualize my neo4j database and look through properties etc, mostly to have a feedback and understand what I put in my database. I tried Neoclipse, but so far it is very buggy and often doesn't load the graph. Is there an