Compact Representation of Large RDF Data Sets for Publishing and Exchange

Abstract

Abstract. Increasingly huge RDF data sets are being published on the Web. Currently, they use different syntaxes of RDF, contain high levels of redundancy and have a plain indivisible structure. All this leads to fuzzy publications, inefficient management, complex processing and lack of scalability. This paper presents a novel RDF representation (HDT) which takes advantage of the structural properties of RDF graphs for splitting and representing, efficiently, three components of RDF data: Header, Dictionary and Triples structure. On-demand management operations can be implemented on top of HDT representation. Experiments show that data sets can be compacted in HDT by more than fifteen times the current naive representation, improving parsing and processing while keeping a consistent publication scheme. For exchanging, specific compression techniques over HDT improve current compression solutions.

Logical Linked Data Compression

“…HDT) to the results. HDT [6] achieves a greater compression for most of the datasets we experimented on. Such high performance can be attributed to its ability to take advantage of the highly skewed RDF data.…”

“…[5] has explored various compression techniques for RDF datasets and observed that most RDF datasets are highly compressible due to it's power-law distribution in term-frequencies, schemas and resources. [6] introduced a more compact representation format, HDT, by decomposing an RDF data source into Header, Dictionary and Triples. A specific compressed version of HDT, HDT-compressed, outperforms most of the universal compressors [6].…”

“…[6] introduced a more compact representation format, HDT, by decomposing an RDF data source into Header, Dictionary and Triples. A specific compressed version of HDT, HDT-compressed, outperforms most of the universal compressors [6]. [19,21] studied the problem of redundancy elimination on RDF graphs in the presence of rules, constraints and queries.…”

“…Earlier RDF compression studies [3,6] have focused on generating a compact representation of RDF. [6] introduced a new compact format called HDT which takes advantage of the powerlaw distribution in term-frequencies, schema and resources in RDF datasets.…”

“…[6] introduced a new compact format called HDT which takes advantage of the powerlaw distribution in term-frequencies, schema and resources in RDF datasets. The compression is achieved due to a compact form representation rather than a reduction in the number of triples.…”