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With the proliferation of database views and curated databases, the issue of data provenance where a piece of data came from and the process by which it arrived in the database is becoming increasingly important, especially in scientiic databases where understanding prove-nance is crucial to the accuracy and currency of data. In this paper we describe an(More)
A schema mapping is a specification that describes how data structured under one schema (the source schema) is to be transformed into data structured under a different schema (the target schema). Schema mappings play a key role in numerous areas of database systems, including database design, information integration, and model management. A fundamental(More)
We study two classes of XML keys introduced in [6], and investigate their associated (finite) implication problems. In contrast to other proposals of keys for XML, these two classes of keys can be reasoned about efficiently. In particular, we show that their (finite) implication problems are finitely axiomatizable and are decidable in square time and cubic(More)
We present an annotation management system for rela-tional databases. In this system, every piece of data in a relation is assumed to have zero or more annotations associated with it and annotations are propagated along, from the source to the output, as data is being transformed through a query. Such an annotation management system is important for(More)
We study two classes of view update problems in relational databases. We are given a source database <i>S</i>, a monotone query <i>Q</i>, and the view <i>Q</i>(<i>S</i>) generated by the query. The first problem that we consider is the classical view deletion problem where we wish to identify a minimal set <i>T</i> of tuples in <i>S</i> whose deletion will(More)
Archiving is important for scientific data, where it is necessary to record all past versions of a database in order to verify findings based upon a specific version. Much scientific data is held in a hierachical format and has a key structure that provides a canonical identification for each element of the hierarchy. In this article, we exploit these(More)
A fundamental problem in information integration is to precisely specify the relationships, called mappings, between schemas. Designing mappings is a time-consuming process. To alleviate this problem, many mapping systems have been developed to assist the design of mappings. However, a benchmark for comparing and evaluating these systems has not yet been(More)