Data Structures for Indexing Triple Table

Semantic-based approaches are relatively new technologies. Some of these technologies are supported by specifications of W3 Consortium, i.e. RDF, SPARQL and so on. There are many areas where semantic data can be utilized, e.g. social networks, annotation of protein sequences etc. From the physical database design point of view, several index data structures are utilized to handle this data. In many cases, the well-known B-tree is used as a basic index supporting some operations. Since the semantic data are multidimensional, a common way is to use a number of B-trees to index the data. In this article, we review other index data structures; we show that we can create only one index when we utilize a multidimensional data structure like the R-tree. We compare a performance of the B-tree indices with the R-tree and some its variants. Our experiments are performed over a huge semantic database, we show advantages and disadvantages of these data structures.