Showing papers by "Peter Buneman published in 2001"

Why and Where: A Characterization of Data Provenance

Abstract: 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 scientific databases where understanding provenance is crucial to the accuracy and currency of data. In this paper we describe an approach to computing provenance when the data of interest has been created by a database query. We adopt a syntactic approach and present results for a general data model that applies to relational databases as well as to hierarchical data such as XML. A novel aspect of our work is a distinction between "why" provenance (refers to the source data that had some influence on the existence of the data) and "where" provenance (refers to the location(s) in the source databases from which the data was extracted).

Keys for XML

Abstract: We discuss the definition of keys for XML documents, payingparticular attention to the concept of a relative key, which is commonly used in hierarchically structured documents and scientific databases. � 2002 Published by Elsevier Science B.V.

Reasoning about Keys for XML

Abstract: We study absolute and relative keys for XML, and investigate their associated decision problems. We argue that these keys are important to many forms of hierarchically structured data including XML documents. In contrast to other proposals of keys for XML, these keys can be reasoned about efficiently. We show that the (finite) satisfiability problem for these keys is trivial, and their (finite) implication problem is finitely axiomatizable and decidable in PTIME in the size of keys.

Constraints for semistructured data and XML

Abstract: Integrity constraints play a fundamental role in database design. We review initial work on the expression of integrity constraints for semistructured data and XML.