36162251
Active XML and Active Query Answers
XML and Web services are revolutioning the automatic management of distributed information, somewhat in the same way that HTML, Web browser and search engines modified human access to world wide information. We argue in this paper that the combination of XML and Web services allows for a novel query answering paradigm, where the exchanged information mixes materialized and intensional, active, information.
14872110
An Electronic Patient Record "on Steroids": Distributed, Peer-to-Peer, Secure and Privacy-conscious
This chapter investigates how an electronic patient record (EPR) document can be managed by a number of active XML (AXML) peers representing hospitals, MDs, insurance companies, and Department of Health. These peers are living on remote servers, laptops, and mobile devices. Each of them provides integrated information/filtering services, or a combination of these, such as a hospital provides information about visits, while an insurance company gives reimbursement reports, and access control on both of them is enforced by both the regulations of the Department of Health, and their own respective privacy policies. The chapter also illustrates how the distributed data can be queried by different users, and how the specified access control rules are enforced along the way. It also investigates how the queries are executed efficiently—only the relevant/permissible parts of the AXML document are exchanged among peers, an AXML peer can fully or partially evaluate a query by delegating some of the computation to filtering peers or information sources.
2598023
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. KADOP leverages several existing technologies and models: it uses distributed hash tables as a peer communication layer, and ActiveXML as a model for constructing and querying the resources in the peer network.
14194921
Active XML, Security and Access Control
XML and Web services are revolutioning the automatic management of distributed information, somewhat in the same way that HTML, Web browsers and search engines modified human access to world wide information. We argue in this paper that the combination of XML and Web services allows for a novel distributed data management paradigm, where the exchanged information mixes materialized and intensional, active, information. We illustrate the flexibility of this approach by presenting Active XML, a language that is based on embedding Web service calls in XML data. We focus on two particular issues, namely security and access control.
965218
Positive active XML
The increasing popularity of XML and Web services have given rise to a new generation of documents, called Active XML documents (AXML), where some of the data is given explicitly while other parts are given intensionally, by means of embedded calls to Web services. Web services in this context can exchange intensional information, using AXML documents as parameters and results.The goal of this paper is to provide a formal foundation for this new generation of AXML documents and services, and to study fundamental issues they raise. We focus on Web services that are (1) monotone and (2) defined declaratively as conjunctive queries over AXML documents. We study the semantics of documents and queries, the confluence of computations, termination and lazy query evaluation.
40120481
Peer-to-peer warehousing of XML resources*
5088023
Detecting changes in XML documents
We present a diff algorithm for XML data. This work is motivated by the support for change control in the context of the Xyleme project that is investigating dynamic warehouses capable of storing massive volumes of XML data. Because of the context, our algorithm has to be very efficient in terms of speed and memory space even at the cost of some loss of quality. Also, it considers, besides insertions, deletions and updates (standard in diffs), a move operation on subtrees that is essential in the context of XML. Intuitively, our diff algorithm uses signatures to match (large) subtrees that were left unchanged between the old and new versions. Such exact matchings are then possibly propagated to ancestors and descendants to obtain more matchings. It also uses XML specific information such as ID attributes. We provide a performance analysis of the algorithm. We show that it runs in average in linear time vs. quadratic time for previous algorithms. We present experiments on synthetic data that confirm the analysis. Since this problem is NP-hard, the linear time is obtained by trading some quality. We present experiments (again on synthetic data) that show that the output of our algorithm is reasonably close to the optimal in terms of quality. Finally we present experiments on a small sample of XML pages found on the Web.
13401760
Sharing Content in Structured P2P Networks
The development of Web standards and technologies has brought new opportunities for large-scale integration of Web content: data sources (such as XML, HTML, or PDF files), distributed applications (accessed via Web Services), and semantic information. At the same time, peerto- peer (P2P) platforms are being developed, and increasingly used for data management at the network scale. We present KADOP, a model, architecture, and system for sharing content in P2P. By building on distributed hash tables technology, XML indexing and query optimization techniques, and on the paradigm of active documents, KADOP enables the publication, discovery, and efficient exploitation of Web content in P2P. Thanks to intensional information, KADOP (i) is capable of run-time dynamic Web service composition, and (i) is open to external resources such as databases or other P2P networks.
1109183
XML Data Integration with Identification
Data integration is the problem of combining data residing at different sources, and providing the user with a virtual view, called global schema, which is independent from the model and the physical origin of the sources. Whereas many data integration systems and theoretical works have been proposed for relational data, not much investigation has been focused yet on XML data integration. Our goal is therefore to address some of its related issues. In particular, we highlight two major issues that emerge in the XML context: (i) the global schema may be characterized by a set of constraints, expressed by means of a DTD and XML integrity constraints, (ii) the concept of node identity requires to introduce semantic criteria to identify nodes coming from different sources. We propose a formal framework for XML data integration systems based on an expressive XML global schema, a set of XML data sources and a set of mappings specified by means of a simple tree language. Then, we define an identification function that aims at globally identifying nodes coming from different sources. Finally, we propose algorithms to answer queries under different assumptions for the mappings.
1233326
Turning the Network into a Database with Active XML
Because of information ubiquity, one observes an important trend towards transferring information management tasks from database systems to networks. We introduce the notion of data ring that can be seen as a network version of a database or a content warehouse. A main goal is to achieve better performance for content management without requiring the acquisition of explicit control over information resources. In this paper, we discuss the main traits of data rings and argue that Active XML provides an appropriate basis for such systems.
46518675
Managing an XML Warehouse in a P2P Context
The paper is about warehousing XML content in a P2P environment. The role of an XML warehouse is to offer a centralized entry point to access a variety of information in an enterprise and provide functionalities to acquire, enrich, monitor and maintain this information. We consider a number of reasons to use a P2P approach to such warehouses, e.g., reducing the cost or sharing the management of information. We mention research issues that are raised.