Catharine M. Wyss

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Discovering functional dependencies (FDs) from an existing relation instance is an important technique in data mining and database design. To date, even the most e cient solutions are exponential in the number of attributes of the relation (n), even when the size of the output is not exponential in n. Lopes et al. developed an algorithm, Dep-Miner, that(More)
In this article, we develop a relational algebra for metadata integration, <i>Federated Interoperable Relational Algebra</i> (FIRA). FIRA has many desirable properties such as compositionality, closure, a deterministic semantics, a modest complexity, support for nested queries, a subalgebra equivalent to canonical Relational Algebra (RA), and robustness(More)
Discovering functional dependencies (FDs) from an existing relation instance is an important technique in data mining and database design. To date, even the most eecient solutions are exponential in the number of attributes of the relation (n), even when the size of the output is not exponential in n. Lopes et al. developed an algorithm, Dep-Miner, that(More)
This paper extends relational processing and optimization to the FISQL/FIRA languages for dynamic schema queries over multidatabases. Dynamic schema queries involve the creation and restructuring of metadata at runtime. We present a full implementation of a FISQL/FIRA engine, which includes subqueries and all transformational capabilities of FISQL/FIRA on(More)
Information integration is not a new problem. By all accounts, language has always taken a multitude of forms, thus the need for translating between different representations of our world has been acute throughout history. With the advent of the World Wide Web, however, this need takes on hitherto unseen dimensions in terms of both difficulty and promise.(More)
In this paper, we describe and situate the TUPELO system for data mapping in relational databases. Automating the discovery of mappings between structured data sources is a long standing and important problem in data management. Starting from user provided example instances of the source and target schemas, TUPELO approaches mapping discovery as search(More)
Automating the discovery of mappings between structured data sources is a long standing and important problem in data management. We discuss the rich history of the problem and the variety of technical solutions advanced in the database community over the previous four decades. Based on this discussion, we develop a basic statement of the data mapping(More)
In this work, we consider augmenting SQL with constructs allowing dynamic restructuring. Dynamic restructuring occurs naturally in a framework including second-order capabilities for integrating metadata and data within single queries. The context and motivating example for this extension is a federation of relational databases, containing semantically(More)
The need for <i>interoperability</i> among databases has increased dramatically with the proliferation of readily available DBMS and application software. Even within a single organization, data from disparate relational databases must be integrated. A framework for interoperability in a federated system of relational databases should be inherently(More)