This report examines the relative advantages of a storage model based on decomposition (of community view relations into binary relations containing a surrogate and one attribute) over conventional n-ary storage models
Identity is that property of an object which distinguishes each object from all others. Identity has been investigated almost independently in general-purpose programming languages and database languages. Its importance is growing as these two environments evolve and merge.We describe a continuum between weak and strong support of identity, and argue for the incorporation of the strong notion of identity at the conceptual level in languages for general purpose programming, database systems and their hybrids. We define a data model that can directly describe complex objects, and show that identity can easily be incorporated in it.Finally, we compare d~erent implementation schemes for identity and argue that a surrogate-based implementation scheme is needed to support the strong notion of identity.
Parallelism is a promising approach to high performance data management. In a highly parallel data server with declustered data placement, an important issue is to exploit parallelism in processing complex queries such as recursive queries. In this paper, we consider the transitive closure of a database relation as a paradigm to study parallel recursive query processing. And we propose two new parallel algorithms for evaluating the transitive closure of a relation in a parallel data server. Performance comparisons based on an analytical model indicate the superior response time of the parallel algorithms over their centralized version. With one hundred nodes, performance gain is between one and two orders of magnitude. One parallel algorithm provides superior response time while the other exhibits better response time/total time trade-off.
Identity is that property of an object which distinguishes each object from all others. Identity has been investigated almost independently in general-purpose programming languages and database languages. Its importance is growing as these two environments evolve and merge.
We describe a continuum between weak and strong support of identity, and argue for the incorporation of the strong notion of identity at the conceptual level in languages for general purpose programming, database systems and their hybrids. We define a data model that can directly describe complex objects, and show that identity can easily be incorporated in it. Finally, we compare different implementation schemes for identity and argue that a surrogate-based implementation scheme is needed to support the strong notion of identity.
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