R2G: foster the use of Graph Databases
Graphs are able to subsume any other kind of data structure and can be employed to flexibly represent databases. The so-called graph databases store, in a logical way, data into nodes and edges. Graph databases are natively used in a multitude of fields such as Bioinformatics, Genomics, Semantic Web, Social Networks and are becoming more and more accepted as a general purpose solution to persist data.
With the advent of the NoSQL movement, Graph Database Management Systems (GDBMSs) are rapidly emerging as an effective and efficient solution to the management of very large data sets in cases where data are naturally represented as a graph and data accesses mainly rely on traversing this graph. As most data sources are stored in relational databases, it is difficult to migrate them to graph databases. In fact, relational databases are a legacy technology inside organizations.
- a model-driven, system-independent methodology for the design of graph databases. Starting from a conceptual representation of the domain of interest expressed in the Entity-Relationship model, we propose a strategy for devising a graph database in which the data accesses for answering queries are minimized. Our methodology relies on a logical model for graph databases, which makes the approach suitable for different GDBMSs.
- a comprehensive approach to the automatic migration of databases from relational to graph storage systems. It includes the conversion of the persistent layer of the application from a relational to a graph data store. We also show how to translate conjunctive SQL queries over the source into graph traversal operations over the target. The translation takes advantage of the integrity constraints defined over the source and try to minimize the number of accesses needed to answer queries over the target. Intuitively, this is achieved by aggregating in the same node data that are likely to occur together in query results.
More details about R2G can be found on the following papers:
- Roberto De Virgilio, Antonio Maccioni, Riccardo Torlone. R2G: a Tool for Migrating Relations to Graphs. 17th International Conference on Extending Database Technology (EDBT 2014), Athens, Greece, 2014.
- Roberto De Virgilio, Antonio Maccioni, Riccardo Torlone. Model-driven design of graph databases. 33rd International Conference on Conceptual Modeling (ER 2014), Atlanta, USA, 2014.