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The efficient execution of multi-criteria queries has gained increasing interest over the last years. In the present paper we propose an R-tree based approach for queries addressing textual as well as geographic filter conditions. Whereas most previous approaches use an index structure optimised for a single criterion adding special treatment for the other(More)
Nowadays developers and end users of data management systems are challenged with the reduction of the "energy consumption footprint" of existing implementations and configurations. In other words, the energy efficiency has to be optimized, either by increasing the performance or by consuming less resources. In fact, there is a big number of factors that(More)
  • Raik Niemann
  • 2015
In the last couple of years it became more difficult for end users of data management system to optimize existing systems for performance and energy consumption. The reasons are the big number of data management systems to chose from, extensive use cases and a variety of hardware configurations. The number of factors that influence the performance and(More)
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Since GNU/Linux became a popular operating system on computer network routers, its packet routing mechanisms attracted more interest. This does not only concern " big " Linux servers acting as a router but more and more small and medium network access devices, such as DSL or cable access devices. Although there are a lot of documents dealing with high(More)
A comparative analysis of energy efficiency of database operations under different workload scenarios ABSTRACT With the continuous increase of online services as well as energy costs, energy consumption becomes a significant cost factor for the evaluation of data center operations. A significant contributor to that is the performance of database servers(More)