Authors:
Giacomo Buratti
1
and
Danilo Montesi
2
Affiliations:
1
University of Camerino, Italy
;
2
University of Bologna, Italy
Keyword(s):
XML, Algebra, Full-Text, Approximate Query.
Related
Ontology
Subjects/Areas/Topics:
Applications
;
Business Analytics
;
Communication and Software Technologies and Architectures
;
Data Engineering
;
Data Warehouses and Data Mining
;
e-Business
;
Enterprise Information Systems
;
Information Retrieval
;
Ontologies and the Semantic Web
;
Pattern Recognition
;
Software Engineering
Abstract:
XQuery Full-Text is the proposed standard language for querying XML documents using either standard or full-text conditions; while full-text conditions can have a boolean or a ranked semantics, standard conditions must be satisfied for an element to be returned. This paper proposes a more general formal model that considers structural, value-based and full-text conditions as desiderata rather than mandatory constraints. The goal is achieved defining a set of relaxation operators that, given a path expression or a selection condition, return a set of relaxed path expressions or selection conditions. Algebraic approximated operators are defined for representing typical queries and returns either elements that perfectly respect the conditions and elements that answer to a relaxed version of the original query. A score reflecting the level of satisfaction of the original query is assigned to each result of the relaxed query.