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Data abstraction and query processing techniques are usually studied in the domain of administrative applications. We present a case-study in the non-standard domain of (multimedia) information retrieval, mainly intended as a feasibility study in favor of the ’database approach’ to data management. Top-N queries form a natural query class when dealing with content retrieval. In the IR field,...
Transformation of nested SQL queries into join queries is advantageous because a nested SQL query can be looked upon as a nested-loop join, which is just one of the several join implementations that may be available in a relational DBMS. In join queries, dangling (unmatched) operand tuples are lost, which causes a problem in transforming nested queries having the aggregate function COUNT between query...
Efficient query processing is one of the key promises of database technology. With the evolution of supported data models—from relational via nested relational to object-oriented—the need for such efficiency has not diminished, and the general problem has increased in complexity. In this paper, we present a heuristics-based, extensible algorithm for the translation of object-oriented query...
We describe a tool for physical database design based on a combination of theoretical and pragmatic approaches. The tool takes as input a relational schema, the workload defined on the schema, and some additional database characteristics and produces as output a physical schema. For the time being, the tool is tuned towards Ingres.
We describe two scenarios of user tasks in which access to multimedia data plays a significant role. Because current multimedia databases cannot support these tasks, we introduce three new requirements on multimedia databases: multimedia objects should be active objects, querying is an interaction process, and query processing uses multiple representations. We discuss three techniques to handle multimedia...
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