847694
Reasoning about XML update constraints
We introduce in this paper a class of constraints for describing howan XML document can evolve, namely XML update constraints. For these constraints, we study the implication problem, giving algorithms and complexity results for constraints of varying expressive power. Besides classical constraint implication, we also consider an instance-based approach. More precisely, we study implication with respect to a current tree instance, resulting from a series of unknown updates. The main motivation of our work is reasoning about data integrity under update restrictions in contexts where owners may lose control over their data, such as in publishing or exchange.
9888780
DBGlobe: a service-oriented P2P system for global computing
The challenge of peer-to-peer computing goes beyond simple file sharing. In the DBGlobe project, we view the multitude of peers carrying data and services as a superdatabase. Our goal is to develop a data management system for modeling, indexing and querying data hosted by such massively distributed, autonomous and possibly mobile peers. We employ a service-oriented approach, in that data are encapsulated in services. Direct querying of data is also supported by an XML-based query language. In this paper, we present our research results along the following topics: (a) infrastructure support, including mobile peers and the creation of context-dependent communities, (b) metadata management for services and peers, including location-dependent data, (c) filters for efficiently routing path queries on hierarchical data, and (d) querying using the AXML language that incorporates service calls inside XML documents.
140229514
Representing and querying XML with incomplete information
We study the representation and querying of XML with incomplete information. We consider a simple model for XML data and their DTDs, a very simple query language, and a representation system for incomplete information in the spirit of the representations systems developed by Imielinski and Lipski for relational databases. In the scenario we consider, the incomplete information about an XML document is continuously enriched by successive queries to the document. We show that our representation system can represent partial information about the source document acquired by successive queries, and that it can be used to intelligently answer new queries. We also consider the impact on complexity of enriching our representation system or query language with additional features. The results suggest that our approach achieves a practically appealing balance between expressiveness and tractability. The research presented here was motivated by the Xyleme project at INRIA, whose objective it to develop a data warehouse for Web XML documents.
43298690
A Test Platform for the INEX Heterogeneous Track
This article presents our work within the INEX 2004 Heterogeneous Track. We focused on taming the structural diversity within the INEX heterogeneous bibliographic corpus. 
 
We demonstrate how semantic models and associated inference techniques can be used to solve the problems raised by the structural diversity within a given XML corpus. The first step automatically extracts a set of concepts from each class of INEX heterogeneous documents. An unified set of concepts is then computed, which synthesizes the interesting concepts from the whole corpus. Individual corpora are connected to the unified set of concepts via conceptual mappings. This approach is implemented as an application of the KadoP platform for peer-to-peer warehousing of XML documents. While this work caters to the structural aspects of XML information retrieval, the extensibility of the KadoP system makes it an interesting test platform in which components developed by several INEX participants could be plugged, exploiting the opportunities of peer-to-peer data and service distribution.
43817205
Constructing and Querying Peer-to-Peer Warehouses of XML Resources
We present KadoP, a distributed infrastructure for warehousing XML resources in a peer-to-peer framework. KadoP allows users to build a shared, distributed repository of resources such as XML documents, semantic information about such documents, Web services, and collections of such items. KadoP2P builds on distributed hash tables as a peer communication layer, and ActiveXML as a model for constructing and querying the resources in the peer network. We describe KadoP's data model, query language, and query processing paradigm.
52829094
Distributed Information Management with XML and Web Services
XML and Web services are revolutioning the automatic management of distributed information, somewhat in the same way HTML, Web browser and search engines modified human access to world wide information. To illustrate, we present Active XML that is based on embedding Web service calls inside XML documents. We mention two particular applications that take advantage of this new technology and novel research issues in this setting. This paper is based primarily on research at INRIA-Futurs in the Gemo Group, around XML and Web services (in particular, the Xyleme, Active XML and Spin projects).
2990663
Extracting schema from semistructured data
Semistructured data is characterized by the lack of any fixed and rigid schema, although typically the data has some implicit structure. While the lack of fixed schema makes extracting semistructured data fairly easy and an attractive goal, presenting and querying such data is greatly impaired. Thus, a critical problem is the discovery of the structure implicit in semistructured data and, subsequently, the recasting of the raw data in terms of this structure. In this paper, we consider a very general form of semistructured data based on labeled, directed graphs. We show that such data can be typed using the greatest fixpoint semantics of monadic datalog programs. We present an algorithm for approximate typing of semistructured data. We establish that the general problem of finding an optimal such typing is NP-hard, but present some heuristics and techniques based on clustering that allow efficient and near-optimal treatment of the problem. We also present some preliminary experimental results.