5 papers · 1 filter
Well-Definedness and Semantic Type-Checking in the Nested Relational Calculus and XQuery
Jan Van den Bussche, Dirk Van Gucht, Stijn Vansummeren
Two natural decision problems regarding the XML query language XQuery are well-definedness and semantic type-checking. We study these problems in the setting of a relational fragme…
On the expressive power of semijoin queries
Dirk Leinders, Jerzy Tyszkiewicz, Jan Van den Bussche
The semijoin algebra is the variant of the relational algebra obtained by replacing the join operator by the semijoin operator. We provide an Ehrenfeucht-Fraissé game, characterizi…
Relational Association Rules: getting WARMeR
Bart Goethals, Jan Van den Bussche
In recent years, the problem of association rule mining in transactional data has been well studied. We propose to extend the discovery of classical association rules to the discov…
Interactive Constrained Association Rule Mining
Bart Goethals, Jan Van den Bussche
We investigate ways to support interactive mining sessions, in the setting of association rule mining. In such sessions, users specify conditions (queries) on the associations to b…
A Tight Upper Bound on the Number of Candidate Patterns
Floris Geerts, Bart Goethals, Jan Van den Bussche
In the context of mining for frequent patterns using the standard levelwise algorithm, the following question arises: given the current level and the current set of frequent patter…