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New Software and Platforms
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Section: New Software and Platforms

Clique Square

RDF data management platform based on Hadoop architecture

Keywords: Map-Reduce - Hadoop - RDF - Big data

Scientific Description

CliqueSquare is a system for storing and querying large RDF graphs relying on Hadoop’s distributed file system (HDFS) and Hadoop’s MapReduce open-source implementation. CliqueSquare is equipped with a unique optimization algorithm capable of generating highly parallelizable flat query plans relying on n-ary equality joins. In addition, it provides a novel partitioning and storage scheme that permits first-level joins to be evaluated locally using efficient map-only joins.

Functional Description

RDF (Ressource Description Framework) is the data format for the semantic web. CliqueSquare allows storing and querying very large volumes of RDF data in a massively parralel fashion in a Hadoop cluster. The system uses its own partitioning and storage model for the RDF triples in the cluster.

CliqueSquare evaluates queries expressed in a dialect of the SPARQL query language. It is particularly efficient when processing complex queries, because it is capable of translating them into MapReduce programs guaranteed to have the minimum number of successive jobs. Given the high overhead of a MapReduce job, this advantage is considerable.