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Database benchmarks are an important tool for database researchers and practitioners that ease the process of making informed comparisons between different database hardware, software and configurations. Large scale web services such as social networks are a major and growing database application area, but currently there are few benchmarks that accurately(More)
The existence and use of standard test collections in information retrieval experimentation allows results to be compared between research groups and over time. Such comparisons, however, are rarely made. Most researchers only report results from their own experiments, a practice that allows lack of overall improvement to go unnoticed. In this paper, we(More)
Scripting is often used in science to create applications via the composition of existing programs. Parallel scripting systems allow the creation of such applications, but each system introduces the need to adopt a somewhat specialized programming model. We present an alternative scripting approach, AMFS Shell, that lets programmers express parallel(More)
Many scientific applications are conceptually built up from independent component tasks as a parameter study, optimization, or other search. Large batches of these tasks may be executed on high-end computing systems, however, the coordination of the independent processes, their data, and their data dependencies is a significant scalability challenge. Many(More)
In order for many-task applications to be attractive candidates for running on high-end supercomputers, they must be able to benefit from the additional compute, I/O, and communication performance provided by high-end HPC hardware relative to clusters, grids, or clouds. Typically this means that the application should use the HPC resource in such a way that(More)
Efficiently utilizing the rapidly increasing concurrency of multi-petaflop computing systems is a significant programming challenge. One approach is to structure applications with an upper layer of many loosely-coupled coarse-grained tasks, each comprising a tightly-coupled parallel function or program. "Many-task" programming models such as functional(More)
Evaluation forums such as TREC allow systematic measurement and comparison of information retrieval techniques. The goal is consistent improvement, based on reliable comparison of the effectiveness of different approaches and systems. In this paper we report experiments to determine whether this goal has been achieved. We ran five publicly available search(More)
Extended Abstract A fundamental goal of information retrieval research is to develop new retrieval techniques, and to demonstrate that they attain improved effectiveness compared to their predecessors. To quantitatively compare IR techniques, the community has developed a range of standard test collections, in particular the TREC collections ; see Voorhees(More)