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We present a shape deenition language, called SDL, for retrieving objects based on shapes contained in the histories associated with these objects. It is a small, yet powerful, language that allows a rich v ariety of queries about the shapes found in historical time sequences. An interesting feature of SDLis its ability to perform blurry matching. A blurry"(More)
In this article, we describe our approach to the compile-time optimization and parallelization of queries for execution in DBS3 or EDS. DBS3 is a shared-memory parallel database system, while the EDS system has a distributed-memory architecture. Because DBS3 implements a parallel dataflow execution model, this approach applies to both architectures. Using(More)
The co.91 of query optimization is ufiected by both the ~eurch apocc und the search atmlegy of the opti,aizer. I~I (1 pumllel ecectrlion environment, Ihe search ap~cc tends lo he much lurger than in the centmlized ca,sc-. This is due to the high number of ezecution okeruutivrs which implies a aignijiconl increase in the op~imisutiofc coal. 118 &a puper, we(More)
In this paper, we present a new algorithm for estimating the size of equality join of multiple database tables. The proposed algorithm, Correlated Sampling, constructs a small space synopsis for each table, which can then be used to provide a quick estimate of the join size of this table with other tables subject to dynamically specified predicate filter(More)
Traditional on-disk row major tables have been the dominant storage mechanism in relational databases for decades. Over the last decade, however, with explosive growth in data volume and demand for faster analytics, has come the recognition that a different data representation is needed. There is widespread agreement that in-memory column-oriented databases(More)