Getting Started with Graph Databases • Hacker News Board

Re: Getting Started with Graph Databases

#31

Post by jonpaine » Thu, Mar 10, 2016, 7:07 PM UTC

dperfect wrote: post #27

jonpaine wrote: post #24

Earlier quoted context omitted.

Index-free-adjacency. There are myriad pros/cons between graph/relational/nosql, but to me, a "real" graph db will have index free adjacency, allowing it to do deep traversals (friend of a friend-of a friend-oaf-oaf....) in constant time. It finds it's value in traversal of deeply connected datasets. Any article or comparison that doesn't at least try to explain index free adjacency isn't going to make a compelling c…

That makes sense. I'm seeing index-free adjacency mentioned in some other comparisons. Sounds pretty cool. So if each node has pointers directly to related nodes (without needing an index lookup), does that also mean that inserts and updates are slower? From what I understand, if you're bypassing the need for an index lookup at query time, you have to pay for that at some other point in time - specifically by looking…

That's right. However, there are still indexes, even if they aren't necessary for traversal. Ideally you'll use an index to find a start node and traverse on from there (or in the case of your question, update from there).

Re: Getting Started with Graph Databases

#32

Post by throwaway41597 » Thu, Mar 10, 2016, 8:09 PM UTC

owen11 wrote: post #18

mitsoz wrote: post #11

I was very interested in the subject, but hated this video. Very superficial, started off with a complicated relational schema to criticize relational databases, but never ended up explaining how a graph database would simplify the problem. I thought that the graph database concepts + language was way more complex than SQL schema + language. Very fast talking and moving of slides, is this supposed to sound or look sm…

Good feedback. I might need similar feedback for my upcoming talk. I am about to give a talk about Cayley (open source graph db written in Go) and I am working on my slides http://oren.github.io/adventure-graphs Let me know what you think and also join us on IRC (#cayley on freenode) if you find it interesting.

TL;DR: graphs are everywhere in the real world, so using a graph DB will be simpler and more efficient; examples of graph queries follow.

Thank you but may I ask who this presentation is for? Because from a quick glance, it's not very deep in technical details. I mean I'm curious about graph databases, but comparing them to vanilla SQL schemas isn't very informative. What I really want to know is what makes them different from denormalized schemas (which is what I expect most people would use).

Re: Getting Started with Graph Databases

#33

Post by marknadal » Thu, Mar 10, 2016, 9:30 PM UTC

rustyrazorblade wrote: post #20

marknadal wrote: post #12

This article overly inflates the complexity of graphs and databases in order to sound fancy. I've written a response that is very direct and shows how simple a graph database can be: https://github.com/amark/gun/wiki/Graph-Databases-101 .

Hi. Presenter here. Honestly the goal wasn't to sound fancy. If you're going to work in the GraphDB world, you're going to come across this terminology. If your concern around my intro is the complexity described of the relational world, well, that's kind of the point. Anyone with at least a few years experience in the RDBMS world has probably come across a project that's spiraled completely out of control with a out…

Sorry for the abrasiveness, I actually liked your overview of table outrage (I should have been positive and mentioned this). What I didn't like is that the article starts right away with mentioning Gremlin - which is very popular within the academic community but difficult for most developers. Honestly anything outside of SQL and MongoDB's query spec can be frightening for devs. Because you are genuinely talking about another language you have to learn. This complexity makes graphs themselves look like they are hard and difficult and for serious people, like machine learning. So I think it is dangerous to introduce people to complicated new query languages in a 101 article because people will feel discouraged that if they can't get past Gremlin then they'll never be able to use graphs at all (despite the fact that they use them all the time, especially on the frontend, without even realizing it). Elsewise I thought you did a good job explaining the problem and even talking about the basics of semantics. Just going down the Gremlin route either scares people off or appeals to the more academic elite.

Re: Getting Started with Graph Databases

#34

Post by phpnode » Fri, Mar 11, 2016, 11:47 AM UTC

marknadal wrote: post #33

rustyrazorblade wrote: post #20

Earlier quoted context omitted.

Hi. Presenter here. Honestly the goal wasn't to sound fancy. If you're going to work in the GraphDB world, you're going to come across this terminology. If your concern around my intro is the complexity described of the relational world, well, that's kind of the point. Anyone with at least a few years experience in the RDBMS world has probably come across a project that's spiraled completely out of control with a out…

Sorry for the abrasiveness, I actually liked your overview of table outrage (I should have been positive and mentioned this). What I didn't like is that the article starts right away with mentioning Gremlin - which is very popular within the academic community but difficult for most developers. Honestly anything outside of SQL and MongoDB's query spec can be frightening for devs. Because you are genuinely talking abo…

Gremlin is a practical query language designed for developers and has very little (maybe zero) usage in academia. SparQL is the more established option which does get some academic (and production) usage, particularly as a lot of research on graph databases has a cross over with semantic web research.

This isn't the first time I've seen you criticise the "academic elite". You seem to use it as a crutch, an excuse for sloppy thinking and poor quality software.

Re: Getting Started with Graph Databases

#35

Post by jmartins » Mon, Mar 14, 2016, 1:57 PM UTC

owen11 wrote: post #18

mitsoz wrote: post #11

I was very interested in the subject, but hated this video. Very superficial, started off with a complicated relational schema to criticize relational databases, but never ended up explaining how a graph database would simplify the problem. I thought that the graph database concepts + language was way more complex than SQL schema + language. Very fast talking and moving of slides, is this supposed to sound or look sm…

Good feedback. I might need similar feedback for my upcoming talk. I am about to give a talk about Cayley (open source graph db written in Go) and I am working on my slides http://oren.github.io/adventure-graphs Let me know what you think and also join us on IRC (#cayley on freenode) if you find it interesting.

there are a slack channel too in gophers.slack.com