Positive Active XML. (2004)

by Serge Abiteboul, Omar Benjelloun, Tova Milo
Venue:In PODS,
Add To MetaCart
Results 11 - 20 of 43

Verifying Recursive Active Documents with Positive Data Tree Rewriting

by Blaise Genest, Anca Muscholl, Zhilin Wu
"... This paper considers a tree-rewriting framework for modeling documents evolving through service calls. We focus on the automatic verification of properties of documents that may contain data from an infinite domain. We establish the boundaries of decidability: while verifying documents with recursiv ..."
Abstract - Cited by 5 (0 self) - Add to MetaCart
This paper considers a tree-rewriting framework for modeling documents evolving through service calls. We focus on the automatic verification of properties of documents that may contain data from an infinite domain. We establish the boundaries of decidability: while verifying documents with recursive calls is undecidable, we obtain decidability as soon as either documents are in the positive-bounded fragment (while calls are unrestricted), or when there is a bound on the number of service calls (bounded model-checking of unrestricted documents). In the latter case, the complexity is NexpTime-complete. Our data tree-rewriting framework resembles Guarded Active XML, a platform handling XML repositories that evolve through web services. The model here captures the basic features of Guarded Active XML and extends it by node renaming and subtree deletion. Digital Object Identifier 10.4230/LIPIcs.FSTTCS.2010.469 1

On the Equivalence of Distributed Systems with Queries and Communication

by Serge Abiteboul, Balder Ten Cate, Yannis Katsis - INTERNATIONAL CONFERENCE ON DATABASE THEORY , 2011
"... Distributed data management systems consist of peers that store, exchange and process data in order to collaboratively achieve a common goal, such as evaluate some query. We study the equivalence of such systems. We model a distributed system by a collection of Active XML documents, i.e., trees augm ..."
Abstract - Cited by 5 (2 self) - Add to MetaCart
Distributed data management systems consist of peers that store, exchange and process data in order to collaboratively achieve a common goal, such as evaluate some query. We study the equivalence of such systems. We model a distributed system by a collection of Active XML documents, i.e., trees augmented with function calls for performing tasks such as sending, receiving and querying data. As our model is quite general, the equivalence problem turns out to be undecidable. However, we exhibit several restrictions of the model, for which equivalence can be effectively decided. We also study the computational complexity of the equivalence problem, and present an axiomatization of equivalence, in the form of a set of equivalence-preserving rewrite rules allowing us to optimize a system by rewriting it into an equivalent, but possibly more efficient system.
(Show Context)

XCraft: A Dynamic Optimizer for the Materialization of Active XML Documents. 2006, COPPE/UFRJ: Rio de Janeiro.Technical Report ES-709/07

by Gabriela Ruberg, Marta Mattoso
"... An active XML (AXML) document contains special tags that represent calls to Web services. Retrieving its contents consists in materializing its data elements by invoking all its embedded service calls in a P2P network. In this process, the results of some service calls are often used as inputs to ot ..."
Abstract - Cited by 4 (4 self) - Add to MetaCart
An active XML (AXML) document contains special tags that represent calls to Web services. Retrieving its contents consists in materializing its data elements by invoking all its embedded service calls in a P2P network. In this process, the results of some service calls are often used as inputs to other calls. Also, usually several peers provide each requested Web service, and peers can collaborate to invoke these services. This implies many equivalent materialization alternatives, with different performance. Optimizing the AXML materialization process is a hard problem, which often involves searching a huge space of solutions. Current techniques for workflow scheduling and distributed query processing are insufficient for this problem, since in AXML materialization: (i) the set of participating
(Show Context)

Checking Satisfiability of Tree Pattern Queries for Active XML Documents

by Hai-tao Ma, Zhong-xiao Hao, Yan Zhu , 2008
"... Abstract. Satisfiability is an important problem of queries for XML documents. This paper focuses on the satisfiability of tree pattern queries for Active XML(AXML for short) documents conforming to a given AXML schema. An AXML document is an XML document where some data is given explicitly and othe ..."
Abstract - Cited by 4 (0 self) - Add to MetaCart
Abstract. Satisfiability is an important problem of queries for XML documents. This paper focuses on the satisfiability of tree pattern queries for Active XML(AXML for short) documents conforming to a given AXML schema. An AXML document is an XML document where some data is given explicitly and other parts are defined intensionally by means of embedded calls to Web services, which can be invoked to generate data. For the efficient evaluation of a query over an AXML document, one should check whether there exists an (A)XML document obtained from the original one by invoking some Web services, on which the query has a non-empty answer. An algorithm for checking satisfiability of tree pattern queries for AXML documents that runs polynomial time is proposed based on tree automata theory. Then experiments were made to verify the utility of satisfiability checking as a preprocessing step in queries procession. Our results show that the check takes a negligible fraction of the time needed for processing the query while often yielding substantial savings.
(Show Context)

Sharing Content in Structured P2P Networks

by Serge Abiteboul, Ioana Manolescu, Nicoleta Preda , 2005
"... 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 ar ..."
Abstract - Cited by 3 (0 self) - Add to MetaCart
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 (�) is capable of run-time dynamic Web service composition, and (��) is open to external resources such as databases or other P2P networks. 1.
(Show Context)

Incremental View Maintenance for Active Documents

by Serge Abiteboul, Pierre Bourhis, Bogdan Marinoiu - BASES DE DONNÉES AVANCÉES, MARSEILLE: FRANCE , 2007
"... In this paper, we develop algorithmic datalog-based foundations for the incremental processing of tree-pattern queries over active documents, i.e. document with incoming streams of data. We define query satisfiability for such documents based on a logic with 3-values: true, false forever, and false ..."
Abstract - Cited by 3 (0 self) - Add to MetaCart
In this paper, we develop algorithmic datalog-based foundations for the incremental processing of tree-pattern queries over active documents, i.e. document with incoming streams of data. We define query satisfiability for such documents based on a logic with 3-values: true, false forever, and false for now. Also, given an active document and a query, part of the document (and in particular, some incoming streams) may become irrelevant for the query of interest. We introduce an incremental algorithm for detecting such useless data and streams, essential for implementing garbage collection. We also provide complexity analysis for the problems we study.
(Show Context)

A Calculus and Algebra for Distributed Data Management

by Serge Abiteboul - in "Symposium on Theoretical Aspects of Computer Science (STACS , 2007
"... Abstract. The sharing of content by communities of users (e.g., scien-tists) in a P2P context remains cumbersome. We argue that main reasons for this is the lack of calculus and algebra for distributed data manage-ment. We present the ActiveXML language that extends the XML lan-guage with features t ..."
Abstract - Cited by 2 (0 self) - Add to MetaCart
Abstract. The sharing of content by communities of users (e.g., scien-tists) in a P2P context remains cumbersome. We argue that main reasons for this is the lack of calculus and algebra for distributed data manage-ment. We present the ActiveXML language that extends the XML lan-guage with features to handle distribution. More precisely, ActiveXML documents are XML documents with a special syntax for specifying the embedding of Web service calls, e.g. XML queries such as XQueries. We also present ActiveXML algebra that extends ActiveXML notably with explicit control of data exchanges. ActiveXML algebra allows describing query plans, and exchanging them between peers. 1
(Show Context)

ARAXA: an object-relational approach to store active XML documents

by Cláudio Ananias Ferraz, Vanessa P. Braganholo, Marta Mattoso
"... Active XML (AXML) documents combine extensional XML data with intentional data defined through Web service calls. The dynamic properties of these documents pose challenges to both storage and data materialization techniques. We present ARAXA, a non-intrusive approach to store AXML documents. It ta ..."
Abstract - Cited by 1 (1 self) - Add to MetaCart
Active XML (AXML) documents combine extensional XML data with intentional data defined through Web service calls. The dynamic properties of these documents pose challenges to both storage and data materialization techniques. We present ARAXA, a non-intrusive approach to store AXML documents. It takes advantage of complex objects from object-relational DBMS to represent both extensional and intentional data. By using a DBMS we benefit from efficient storage tools and query engine. We have defined a storage mechanism with a methodology to materialize AXML documents at query time. We have also implemented a prototype of ARAXA. Our experimental results show that our approach is scalable and extensible.
(Show Context)

Active XML, security and access control

by Serge Abiteboul, Omar Benjelloun, Bogdan Cautis, Tova Milo, Xyleme Sa - in SBBD’04, 2004
"... 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 dist ..."
Abstract - Cited by 1 (0 self) - Add to MetaCart
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. 1.
(Show Context)

BiLog: Spatial Logics for Bigraphs

by Giovanni Conforti, Damiano Macedonio, Vladimiro Sassone , 2005
"... Bigraphs are emerging as a (meta-)model for concurrent calculi, like CCS, ambients, πcalculus, and Petri nets. They are built orthogonally on two structures: a hierarchical place graph for locations and a link (hyper-)graph for connections. Aiming at describing bigraphical structures, we introduce a ..."
Abstract - Cited by 1 (0 self) - Add to MetaCart
Bigraphs are emerging as a (meta-)model for concurrent calculi, like CCS, ambients, πcalculus, and Petri nets. They are built orthogonally on two structures: a hierarchical place graph for locations and a link (hyper-)graph for connections. Aiming at describing bigraphical structures, we introduce a general framework, BiLog, whose formulae describe arrows in monoidal categories. We then instantiate the framework to bigraphical structures and we obtain a logic that is a natural composition of a place graph logic and a link graph logic. We explore the concepts of separation and sharing in these logics and we prove that they generalise well known spatial logics for trees, graphs and tree contexts. As an application, we show how XML data with links and web services can be modelled by bigraphs and described by BiLog. The framework can be extended by introducing dynamics in the model and a standard temporal modality in the logic. However, in some cases, temporal modalities can be already expressed in the static framework. To testify this, we show how to encode a minimal spatial logic for CCS in an instance of BiLog.