Performance Analysis and Optimization of Semantic Queries

Today, the usage of triplestores increases in complex computer systems. Traditionally, they are used for representing static knowledge. In the last years, systems started using semantic triplestores in highly dynamic scenarios, e.g., in the context of civil protection. In these use cases, performance characteristics are more and more important. There are various aspects influencing the query performance. We have noticed that already the query structure has a significant impact on the execution time. SPARQL is a widely used standard for querying triplestores. In this work, we have developed SPARQL query patterns and evaluated their performance characteristics. For this a literature review was done to select a suitable benchmark. As a result we provide eight recommendations for formulating SPARQL queries. These can be easily used by everybody without a deeper knowledge about the implementation of the triplestore, which contains the desired data.