Alan S. Wagner

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In this paper, we investigate the approach of using low cost PC cluster to parallelize the computation of iceberg-cube queries. We concentrate on techniques directed towards online querying of large, high-dimensional datasets where it is assumed that the total cube has net been precomputed. The algorithmic space we explore considers trade-offs between(More)
In this paper, we describe the design, implementation, and modeling of a runtime kernel to support the processor farm paradigm on multicomputers. We present a general topology-independent framework for obtaining performance models to predict the performance of the start-up, steady-state, and wind-down phases of a processor farm. An algorithm is described,(More)
Message passing programs commonly use buffers to avoid unnecessary synchronizations and to improve performance by overlapping communication with computation. Unfortunately, using buffers makes the program no longer portable, potentially unable to complete on systems without a sufficient number of buffers. Effective buffer use entails that the minimum number(More)
An important issue in the design of algorithms for a hypercube multiprocessor is to minimize communication overhead by matching the computational structure of the algorithm to the underlying physical structure ofthe machine. One computational structure of particular interest is binary trees. Although in general any tree can be embedded in a sufficiently(More)
We present an algorithm for correcting communication errors using delivered and undelivered messages. It is used to suggest corrective measures to remove errors introduced by typographical errors in message passing systems like PVM and MPI. The paper focuses on the validity of the algorithm by proving that for a nontrivial number of errors the algorithm can(More)