Max De Marzi

Aug 16 2012

Random

Getting a Big Neo4j Test Box for Cheap!

When embarking on a new Neo4j project, one of the things you have to figure out is where to run it. Most of the time the answer is just your laptop. Other times, using Heroku works great. However, if you are at the stage of your testing where you have billions of nodes and relationships, you need something a little bigger.

If you are not ready to commit to purchasing a 100k server for testing, then I suggest you borrow one for a short time. You can try to spin up an Amazon EC2 instance, the high memory large ones go up to 60 gigs of RAM. But what if you need more? Lots more?
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Tagged big data, graph database, neo4j

Aug 13 2012

6 Comments

Random

Neo4j Internals

An overview of Neo4j Internals

View more presentations from Tobias Lindaaker

It is interesting to see how node, relationship and property records are stored differently on disk and in the cache.

It is all linked lists of fixed size records on disk. Properties are stored as a linked list of property records, each holding a key and value and pointing to the next property. Each node and relationship references its first property record. The Nodes also reference the first relationship in its relationship chain. Each Relationship references its start and end node. It also references the previous and next relationship record for the start and end node respectively.
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Tagged graph database, neo4j, nosql

Aug 10 2012

11 Comments

Problems, Random

Summarize Opinions with a Graph – Part 1

How does the saying go? Opinions are like bellybuttons, everybody’s got one? So let’s say you have an opinion that NOSQL is not for you. Maybe you read my blog and think this Graph Database stuff is great for recommendation engines and path finding and maybe some other stuff, but you got really hard problems and it can’t help you.

I am going to try to show you that a graph database can help you solve your really hard problems if you can frame your problem in terms of a graph. Did I say “you”? I meant anybody, specially Ph.D. students. One trick is to search for “graph based approach to” and your problem.
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Tagged graph, nosql, word graph

Jul 18 2012

1 Comment

Cypher

HCIR 2012

A tweet from RiparianData caught my eye the other day:

https://twitter.com/RiparianData/status/222319315800698880

I built getvouched.com with this idea of “expert and expertise discovery” using skill based vouching adjusted by the distance from searcher to target as a way to find rank. So I dug in and found out that Human-computer Information Retrieval (HCIR) combines research from the fields of human-computer interaction (HCI) and information retrieval (IR), placing an emphasis on human involvement in search activities.

The HCIR challenge for this years symposium includes “hiring,” “assembling a conference program,” and “finding people to deliver patent research or expert testimony” as summarized by Patrick Durusau.
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Tagged cypher, github, graph database, hcir, neo4j, relationship graph

Jul 03 2012

1 Comment

Neography, Random

Graph Generator

Update: Code to this project is available on Github.

In the US Air Guitar Championships, competitors use their talents to fret on an “invisible” guitar to rock a live crowd and deliver a performance that transcends the imitation of a real guitar and becomes an art form in and of itself. The key factor that determines the winner is having the elusive quality of “Airness“. When considering using Neo4j in a project, one of the key considerations is having a domain model that yields itself to a graph representation. In other words, does your data have “Graphiness“. However, it didn’t dawn on me until recently that when starting a proof of concept, you probably don’t have that data (or enough of it) or maybe your security guys won’t let you within 100 miles of the company production data with this newfangled nosql thingamajig.
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Tagged big data, graph database, neo4j, ruby

Jul 02 2012

6 Comments

Java

Batch Importer – Part 3

At the end of February, we took a look at Michael Hunger’s Batch Importer. It is a great tool to load millions of nodes and relationships into Neo4j quickly. The only thing it was missing was Indexing… I say was, because I just submitted a pull request to add this feature. Let’s go through how it was done so you get an idea of what the Neo4j Batch Import API looks like, and in the next blog post I’ll show you how to generate data to take advantage of it.
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Tagged big data, github, graph database, java, neo4j

Jun 18 2012

5 Comments

Cypher

Personalization with Cypher

You hopefully have seen a TV commercial from “The Man Your Man Could Smell Like” marketing campaign put on by Old Spice, and you may have seen some of the over 100 videos Isaiah Mustafa appeared in responding to comments made on Twitter. This is a great example of personalization, and today you’ll learn how you can bring some personalization to your application, and you won’t need muscles or a horse.

We’re going to dust off the Neoflix project from the beginning of the year and add a few features. It has been updated to work on Neo4j version 1.7 and allows searching for movies that have a quote. Thanks to Jenn Alons and Vince Cima for the bug fixes during WindyCityDB.
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Tagged cypher, graph database, movies, neo4j

May 31 2012

2 Comments

Random, Visualization

Key Players

In the late 90s Michael Jordan, Scottie Pippen, and Dennis Rodman of the Chicago Bulls dominated the basketball court. They were the key players of the Chicago Bulls, and dominated the NBA offensively and defensively. When exploring a social network you’ll want to find who the key players are for a variety of reasons:

Disrupt: Who should be removed from the network to disrupt it?
Protect: Who should be protected in order to keep the network functioning?
Influence: Who should be influenced in order to change social opinion?
Learn: Who should be questioned in order to know what is going on?
Redirect: Who should be moved to alter social flows?
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Tagged centrality, graph, visualization

May 09 2012

3 Comments

Random

Relationships

When working with relational databases, the join tables are sometimes treated as second class citizens. If they are lucky, they’ll get some additional fields, but are often just placeholder tables connecting your main object tables together. It leads you to think about objects first, and relationships second. With graphs, you will want to switch up your thinking. You want to start thinking about how things are connected. Think about the different ways things are connected. Two people can be friends, co-workers, and neighbors all at the same time.
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Tagged graph database, relationship graph

May 06 2012

2 Comments

Gremlin