The “CrunchBase use-case” – part 2 – A short introduction


Where to start: existing data scheme and API

This series already tells in it’s name what the use case is: The “CrunchBase”.  On their website they speak for themselves to explain what it is: “CrunchBase is the free database of technology companies, people, and investors that anyone can edit.”. There are many reasons why this was chosen as a use-case. One important reason is that all data behind the CrunchBase service is licensed under Creative-Commons-Attribution (CC-BY) license. So it’s freely available data of high-tech companies, people and investors.

Currently there are more than 40.000 different companies, 51.000 different people and 4.200 different investors in the database. The flood of information is big and the scale of connectivity even bigger. The graph represented by the nodes could be even bigger than that but because of the limiting factors of current relational database technology it’s not feasible to try to do that.

sones GraphDB is coming to the rescue: because it’s optimized to handle huge datasets of strongly connected data. Since the CrunchBase data could be uses as a starting point to drive connectivity to even greater detail it’s a great use-case to show these migration and handling.

Thankfully the developers at CrunchBase already made one or two steps into an object oriented world by offering an API which answers queries in JSON format. By using this API everyone can access the complete data set in a very structured way. That’s both good and bad. Because the used technologies don’t offer a way to represent linked objects they had to use what we call “relational helpers”. For example: A person founded a company. (person and company being a JSON object). There’s no standardized way to model a relationship between those two. So what the CrunchBase developers did is they added an unique-Identifier to each object. And they added a new object which is uses as a “relational helper”-object. The only purpose of these helper objects is to point towards a unique-identifier of another object type. So in our example the relationship attribute of the person object is not pointing directly to a specific company or relationship, but it’s pointing to the helper object which stores the information which unique-identifier of which object type is meant by that link.

To visualize this here’s the data scheme behind the CrunchBase (+all currently available links):

As you can see there are many more “relational helper” dead-ends in the scheme. What an application had to do up until now is to resolve these dead-ends by going the extra mile. So instead of retrieving a person and all relationships, and with them all data that one would expect, the application has to split the data into many queries to internally build a structure which essentially is a graph.

Another example would be the company object. Like the name implies all data of a company is stored there. It holds an attribute called investments which isn’t a primitive data type (like a number or text) but a user defined complex data type. This user defined data type is called List<FundingRoundStructure>. So it’s a simple list of FundingRoundStructure objects.

When we take a look at the FundingRoundStructure there’s an attribute called company which is made up by the user defined data type CompanyStructure. This CompanyStructure is one of these dead-ends because there’s just a name and a unique-id. The application now needs retrieve the right company object with this unique-id to access the company information.

Simple things told in a simple way: No matter where you start, you always will end up in a dead-end which will force you to start over with the information you found in that dead-end. It’s not user-friendly nor easy to implement.

The good news is that there is a way to handle this type of data and links between data in a very easy way. The sones GraphDB provides a rich set of features to make the life of developers and users easier. In that context: If we would like to know which companies also received funding from the same investor like let’s say the company “facebook” the only thing necessary would be one short query. Beside that those “relational helpers” are redundant information. That means in a graph database this information would be stored in the form of edges but not in any helper objects.

The reason why the developers of CrunchBase had to use these helpers is that JSON and the relational table behind it isn’t able to directly store this information or to query it directly. To learn more about those relational tables and databases try this link.

I want to end this part of the series with a picture of the above relational diagram (without the arrows and connections).

The next part of the series will show how we can access the available information and how a graph scheme starts to evolve.

, , ,

  1. #1 by Pedro Araújo on August 9, 2012 - 11:15

    Hi,

    Great article. I would like to see the diagrams you mention (the images are broken). Can you fix them?

    Thanks and keep up the good work.

    Pedro Araújo

Comments are closed.