Posts

Why Do We Need an LDBC SNB-Specific Workload Driver?

Tags:
SNB , DRIVER , INTERACTIVE

In a previous 3-part blog series we touched upon the difficulties of executing the LDBC SNB
Interactive (SNB) workload, while achieving good performance and
scalability. What we didn’t discuss is why these difficulties were
unique to SNB, and what aspects of the way we perform workload execution
are scientific contributions - novel solutions to previously unsolved
problems. This post will highlight the differences between SNB and more …

Event Driven Post Generation in Datagen

Tags:
DATAGEN , SOCIAL NETWORK , SNB

As discussed in previous posts, one of the features that makes Datagen
more realistic is the fact that the activity volume of the simulated
Persons is not uniform, but forms spikes. In this blog entry I want to
explain more in depth how this is actually implemented inside of the
generator.

First of all, I start with a few basics of how Datagen works internally.
In Datagen, once the person graph has been created (persons and their
relationships), …

The LDBC Datagen Community Structure

Tags:
DATAGEN , SOCIAL NETWORK , SNB

This blog entry is about one of the features of DATAGEN that makes it
different from other synthetic graph generators that can be found in the
literature: the community structure of the graph.

When generating synthetic graphs, one must not only pay attention to
quantitative measures such as the number of nodes and edges, but also to
other more qualitative characteristics such as the degree distribution,
clustering coefficient. Real graphs, and …

OWL-Empowered SPARQL Query Optimization

Tags:
DEVELOPER , INDUSTRY

The Linked Data paradigm has become the prominent enabler for sharing
huge volumes of data using Semantic Web technologies, and has created
novel challenges for non-relational data management systems, such as RDF
and graph engines. Efficient data access through queries is perhaps the
most important data management task, and is enabled through query
optimization techniques, which amount to the discovery of optimal or
close to optimal execution …

When talking about DATAGEN and other graph generators with social
network characteristics, our attention is typically borrowed by the
friendship subgraph and/or its structure. However, a social graph is
more than a bunch of people being connected by friendship relations, but
has a lot more of other things is worth to look at. With a quick view to
commercial social networks like Facebook, Twitter or Google+, one can
easily identify a lot of other …