AQAX: A System for Approximate XML Query Answers

2003

¾ (eXploring XML data), a system for efficiently querying XML data and visually exploring answer sets, with a special focus on the novel user interface for interaction with the query result. The process of querying XML documents is performed interactively and in a completely graphical manner. Special attention was paid to simplicity of the user interface: In a first step the user submits a query to the system and gets the result presented in the form of a Complete Answer Aggregate (CAA).

International Conference on Data Engineering, 2003

This paper describes £ ¥ ¤ (eXploring XML data), a system for efficiently querying XML data and visually exploring answer sets, with a special focus on the novel user interface for interaction with the query result. The process of querying XML documents is performed interactively and in a completely graphical manner. Special attention was paid to simplicity of the user interface: In a first step the user submits a query to the system and gets the result presented in the form of a Complete Answer Aggregate (CAA). CAAs visually (re)present the answer space in a compact form and thus provide a good overview over the set of all answers. They offer a rich variety of presentation modes and exploration techniques which are used in the second step to interactively explore the answer space.

Studies in Fuzziness and Soft Computing, 2006

XML was born to represent, exchange and publish information on the Web, but now it has spread in many other applications. Due to this success, the W3C has proposed a new query language, XQuery, specifically designed to query XML data. XQuery allows to obtain exact answers to queries; however when applied to large XML repositories or warehouses, such precise queries may require high response times. Our research proposes a methodology for the semi-automatic derivation of summarized documents (synopses) for massive, heterogeneous XML data-sets, with the final aim of producing query transformation rules from queries on the original data-sets to queries on the summarized data-set.

World Wide Web, 2005

XQuery, the standard query language for XML, is increasingly popular among computer scientists with SQL background, since XQuery and SQL require comparable skills. However, these experts are limited in number, and the availability of easier XQuery "dialects" could be extremely valuable. With this motivation in mind, we designed XQBE, a visual dialect of XQuery inspired by the QBE language (Query by Example). Coherent with the hierarchical nature of XML, XQBE uses one or more hierarchical structures to denote the input documents and one structure to denote the document produced in output. These structures are annotated to express selection predicates; explicit binding edges connecting the nodes of these structures visualize the input/output mappings. This paper presents XQBE through several examples and describes the main features of our implementation of the language, a visual editor coupled with an XQBE-to-XQuery translator. Indeed, the XQBE front-end is a general purpose user-friendly visual query interface, capable of providing access to any data storage system that exposes XQuery APIs. Available schema information can be exploited to guide users in querying data sets they are not familiar with. Also, switching between the visual and textual versions of the same query could be helpful for XQuery learners.

2003

XML has been recognized as a promising language for data exchange over the Internet. A number of query languages have been proposed for querying XML data. Most of those languages are path-expression based. One difficulty in forming path-expression based queries is that users have to know the structure of XML data against which the queries were issued. In this paper, we describe a DTD-driven visual query interface for XML database systems. With such an interface, a user can easily form path-expression based queries by clicking elements in the DTD tree displayed on the screen and supplying conditions if necessary. The interface and the query generation process are described in detail.

2007

Abstract XML is a rather verbose representation of semistructured data, which may require huge amounts of storage space. We propose a summarized representation of XML data, based on the concept of instance pattern, which can both provide succinct information and be directly queried. The physical representation of instance patterns exploits itemsets or association rules to summarize the content of XML datasets.

Lecture Notes in Computer Science, 2007

XML has become the standard format for information representation and data exchange. The heterogeneity nature of XML data creates the need for approximate query answering. In this paper, we present a cooperative XML (CoXML) system that provides user-specific approximate query answering. The key features of the system include: 1) a query relaxation language that allows users to specify approximate search conditions and to control the approximate search process; 2) a relaxation index structure for systematic and scalable query relaxation; and 3) both content and structure similarity metrics for evaluating the relevancies of approximate answers. We evaluate our system with the INEX 05 test collections. The results reveal that our language allows users to effectively specify their relaxation specifications and thus enables the system to provide answers with more relevancy. The results also demonstrate the effectiveness of the similarity metrics. Further, compared to other systems in INEX 05, our relaxation features enable our system to retrieve approximate answers with more relevancy.

2001

Abstract The rapid evolution of XML from a mere data exchange format to a universal syntax for encoding domain-specific information raises the need for new query languages specifically conceived to address the characteristics of XML. Such languages should be able not only to extract information from XML documents, but also to apply powerful transformation and restructuring operators, based on a well-defined semantics.

2005

Abstract The spreading of XML data in many contexts of modern computing infrastructures and systems causes a pressing need for adequate XML querying capabilities; to address this need, the W3C is proposing XQuery as the standard query language for XML, with a language paradigm and a syntactic flavor comparable to the SQL relational language. XQuery is designed for meeting the requirements of skilled database programmers; its inherent complexity makes the new language unsuited to unskilled users.

Lecture Notes in Computer Science, 2004

XQuery is increasingly popular among computer scientists with a SQL background, since queries in XQuery and SQL require comparable skills to be formulated. However, the number of these experts is limited, and the availability of easier XQuery "dialects" could be extremely valuable. Something similar happened with QBE, initially proposed as an alternative to SQL, that has then become popular as the user-friendly query language supported by MS Access. We designed and implemented XQBE, a visual dialect of XQuery that uses hierarchical structures, coherent with the hierarchical nature of XML, to denote the input and output documents. In this demonstration we brie¤y introduce XQBE; we then describe how our implementation generates the XQuery translation of the visual queries and also how the XQBE translation of an XQuery statement is generated, provided that XQBE is expressive enough for that query.