There are numerous approaches towards quantifying the performance of NoSQL datastores with respect to dimensions that are notoriously hard to capture such as staleness or consistency in general. Many of these approaches, though, are built on assumptions regarding the underlying infrastructure or the test scenario and may lead to invalid results, if those assumptions do not hold. As a consequenc...

Various types of NoSQL databases may present a sound alternative to relational databases in eInfrastructures that require managing and analysing data supplied from disparate sources. This work considers a few use cases where particular types of NoSQL databases – triple stores and graph databases – may be a natural choice for scalable data services. The purpose of this work is to brief on the ex...

In den letzten Jahren entstanden verschiedene Open-SourceSysteme, die mit fundamentalen Konzepten und Regeln relationaler Datenbanksysteme brachen, um die Verwaltung von Daten in speziellen Einsatzbereichen zu optimieren. Die wesentlichen Gründe für die Entwicklung dieser so genannten NoSQL-Systeme sind jedoch nicht SQL oder das relationale Datenbankmodell, sondern sie ist auf die Implementieru...

Ontologies provide shared and reusable pieces of knowledge about a specific domain. Building an ontology by hand is a very hard and prone to errors task. Ontology learning from existing resources provides a good solution to this issue. Databases are widely used to store data. They were often considered as the most reliable sources for knowledge extraction. NOSQL databases are more and more used...

This work focuses on performance and scalability of different policies for solving queries on large noSQL databases with clusters. Distribution of data and queries are amongst the main problems, given the distributed nature of clusters: basically a set of networked computers. The basic centralized model (for both, data and processing) is used as a departure point and different distributed confi...

In recent years, various distributed NoSQL datastores have been developed that offer horizontal scalability and higher availability than traditional relational databases, but fewer querying options and only reduced consistency guarantees. The diversity of the design space makes it difficult to understand the performance implications of individual system designs. Existing benchmarking tools meas...