66 research outputs found
Semantically annotated hypermedia services
No full textHypermedia systems’ researchers investigate the various approaches in the way documents and resources are linked, navigated and stored in a distributed environment. Unfortunately, those systems fail to provide effortlessly usable discrete services, since it is difficult both to discover and to invoke any of them. This paper proposes the usage of emerging technologies that try to augment the Web resources with semantics in order to provide Hypermedia services that can be easily discovered, and integrated by potential third party developers. In this context, we analyze the benefits for the Hypermedia community upon the adoption of Semantic Web technologies for the description of Hypermedia services, and we implement an initial corresponding ontology
Scaling the Memory Power Wall with DRAM-Aware Data Management
No full textImproving the energy efficiency of database systems has emerged as an important topic of research over the past few years. While significant attention has been paid to optimizing the power consumption of tradition disk-based databases, little attention has been paid to the growing cost of DRAM power consumption in main-memory databases (MMDB). In this paper, we bridge this divide by examining power– performance tradeoffs involved in designing MMDBs. In doing so, we first show how DRAM will soon emerge as the dominating source of power consumption in emerging MMDB servers unlike traditional database servers, where CPU power consumption overshadows that of DRAM. Second, we show that using DRAM frequency scaling and power-down modes can provide substantial improvement in performance/Watt under both transactional and analytical workloads. This, again contradicts rules of thumb established for traditional servers, where the most energy-efficient configuration is often the one with highest performance. Based on our observations, we argue that the long-overlooked task of optimizing DRAM power consumption should henceforth be considered a first-class citizen in designing MMDBs. In doing so, we highlight several promising research directions and identify key design challenges that must be overcome towards achieving this goal.DIA
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