In the last post of our “Neo4j Modelling for Beginners” series,we looked at bidirectional relationships. In this post, we compare the implications of qualifying relationships byusing different relationship types versus using relationship properties.Properties as QualifiersLet’s say we want to model movie ratings in Neo4j. People have an option to rate a movie with 1 to 5 stars. One way ofmodelling this, and perhaps the first one that springs into mind, is creating a RATED relationship with a ratingproperty that takes on 5 different values: integers 1 though 5.Writing queries using this model is fairly straightforward in both Java and Cypher....
Transitioning from the relational world to the beautiful world of graphs requires a shift in thinking about data. Althoughgraphs are often much more intuitive than tables, there are certain mistakes peopletend to make when modelling their data as a graph for the first time. In this article, we look at one common sourceof confusion: bidirectional relationships.Directed RelationshipsRelationships in Neo4j must have a type, giving the relationship a semantic meaning, and a direction. Frequently, thedirection becomes part of the relationship’s meaning. In other words, the relationship would be ambiguous without it.For example, the following graph shows that the Czech Republic DEFEATED...
I have just finished a year-long MSc. program in Computing at Imperial College London. My thesis was called GraphAware:Towards Online Analytical Processing in Graph Databases, which you can freely download. It’s not an easy, cover-to-coverread, but there might be some interesting parts, even if you don’t go through all the (over 100) pages.First of all, the overview of Neo4j architecture in Section 2.4 could be helpful for trying to understand how Neo4j worksand, in particular, how it stores its data. Section 5.1 is a good introduction to the GraphAware Framework’s architecturefor people who would like to dig deeper into it...
S laskavým svolením organizátorů konference WebExpo si dovoluji veřejně zpřístupnit záznam své přednášky o Neo4j. Enjoy! WebExpo Prague 2012 - Introduction to Neo4j (Czech) from bachmanm
Letos jsem se poprvé zúčastnil konference WebExpo a sepsal několik postřehů.Motivace Na WebExpo jsem se vydal hned z několika důvodů. Prvním impulsem byl můj kamarád Honza Šrůtek, který plánoval na konferenci přednášet už podruhé a po shlédnutí mé přednášky na Neo4j User Group v Londýně navrhnul, zda bych ji nechtěl vypilovat a rozšířit řady řečníků na WebExpo. Rychlá kontrola Googlu ukázala, že se o Neo4j v ČR zatím příliš nemluví. Za poslední rok jsem s touto open-source grafovou databází pracoval poměrně intenzivně a získal upřímné přesvědčení, že může mnoha vývojářům, kteří řeší problémy s hustě propojenými daty, významně usnadnit práci. Naposledy...