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The Open Provenance Model core specification (v1.1)
This document contains the specification of the Open Provenance Model (v1.1) resulting from a community effort to achieve inter-operability in the Provenances Challenge series. Expand
DTDs versus XML schema: a practical study
It turns out that at present real-world XSDs only sparingly use the new features introduced by XML Schema: on a structural level the vast majority of them can already be defined by DTDs. Expand
The Open Provenance Model (v1.01)
The Open Provenance Model is introduced, a model for provenance that is designed to meet the following requirements: to allow provenance information to be exchanged between systems, by means of a compatibility layer based on a shared provenance model. Expand
Temporal versus first-order logic to query temporal databases
It is proved here that there are first-order logic queries on the timestamp representation that are not expressible in (extended) temporal logic. Expand
Simulation of the nested relational algebra by the flat relational algebra, with an application to the complexity of evaluating powerset algebra expressions
  • J. Bussche
  • Computer Science, Mathematics
  • Theor. Comput. Sci.
  • 6 March 2001
It is shown that when only unary flat relations are into play, any powerset algebra expression is either equivalent to a nested algebra expression, or its evaluation will produce intermediate results of exponential size. Expand
Towards a theory of spatial database queries
Relational Association Rules: Getting WARMeR
This work proposes to extend the discovery of classical association rules to theiscovery of association rules of conjunctive queries in arbitrary relational data, inspired by the WARMR algorithm, developed by Dehaspe and Toivonen, that discovers association rules over a limited set of conj unctive queries. Expand
Mining tree queries in a graph
An algorithm for mining tree-shaped patterns in a large graph that has a number of provable optimality properties, which are based on the theory of conjunctive database queries, is presented. Expand
Temporal Connectives versus Explicit Timestamps in Temporal Query Languages
It is shown that first-order future temporal logic is strictly less powerful than the relational calculus with explicit timestamps, and a version of fixpoint logic with left and right moves lies between the explicit timestamp versions of first- order and fix point logic. Expand
Concepts for Graph-Oriented Object Manipulation
This work represents different kinds of database interactions by means of a uniform graph-transformation framework based on pattern matching, and incorporates viewing and gives a formal definition of browsing. Expand