Reasoning & Querying – State of the Art

Various query languages for Web and Semantic Web data, both for practical use and as an area of research in the scientific community, have emerged in recent years. At the same time, the broad adoption of the internet where keyword search is used in many applications, e.g. search engines, has familiarized casual users with using keyword queries to retrieve information on the internet. Unlike this easy-to-use querying, traditional query languages require knowledge of the language itself as well as of the data to be queried. Keyword-based query languages for XML and RDF bridge the gap between the two, aiming at enabling simple querying of semi-structured data, which is relevant e.g. in the context of the emerging Semantic Web. This article presents an overview of the field of keyword querying for XML and RDF

TIMBER: A native XML database

This paper describes the overall design and architecture of the Timber XML database system currently being implemented at the University of Michigan. The system is based upon a bulk algebra for manipulating trees, and natively stores XML. New access methods have been developed to evaluate queries in the XML context, and new cost estimation and query optimization techniques have also been developed. We present performance numbers to support some of our design decisions. We believe that the key intellectual contribution of this system is a comprehensive set-at-a-time query processing ability in a native XML store, with all the standard components of relational query processing, including algebraic rewriting and a cost-based optimizer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42328/1/20110274.pd

Level based labeling scheme for extensible markup language (XML) data processing

Thesis (Master)--Izmir Institute of Technology, Computer Engineering, Izmir, 2010Includes bibliographical references (leaves: 56-57)Text in English; Abstract: Turkish and Englishx, 70 leavesWith the continuous growth of data in businesses and the increasing demand for reaching that data immediately, raised the need of having real time data warehouses. In order to provide such a system, the ETL mechanism will need to be very efficient on updating data. From the literature surveys, it has been observed that there are many studies performed on efficient update of the relational data, while there is limited amount of study on updating the XML data. With the extensible structure and effective performance on data exchange, the usage of XML data structure is increasing day by day. Like relational databases, real time XML databases also need to be updated continuously. The hierarchic characteristic of XML required the usage of tree representations for indexing the data since they provide necessary means to capture different relationships between the nodes. The principal purpose of this study is to define and compare algorithms which label the XML tree with an effective update mechanism. Proposed labeling algorithms aim to provide a mechanism to query and update the XML data by defining all relations between the nodes. In the experimental evaluation part of this thesis, all algorithms is examined and tested with an existing labeling algorithm

XML Standardized W3C Tool for effective communication between B2B or B2C Applications

XML is becoming a standard for communicating the information or data over the internet. The shift from SGML to XML has created new demands for managing the structured documents. Many XML documents will be transient representations for the purpose of data exchange between different types of applications, but there will also be a need for effective means to manage persistent XML data as a database. In this paper we explore the different types of XML documents and XML databases. The purpose of the paper is not to suggest this technology is covering all the features necessary for effective communication of data between applications. Instead the purpose is to initiate discussion of the requirements arising from document collections, to offer a context in which to evaluate current and future solutions, and to encourage the develop ment of proper models and systems for XML database management. Our discussion addresses issues arising from data modeling, data definition, and data manipulation. In future, XML will become the standard for communicating data between business - to - business applications, inventory database access and sharing, integration of commercial transactions, and workflo

Automatic mapping of XML documents into relational database

Extensible Markup Language (XML) nowadays is one of the most important standard media used for exchanging and representing data through the Internet. Storing, updating and retrieving the huge amount of web services data such as XML is an attractive area of research for researchers and database vendors. In this thesis, we propose and develop a new mapping model, called MAXDOR, for storing, rebuilding, updating and querying XML documents using a relational database without making use of any XML schemas in the mapping process. The model addressed the problem of solving the structural hole between ordered hierarchical XML and unordered tabular relational database to enable us to use relational database systems for storing, updating and querying XML data. A multiple link list is used to maintain XML document structure, manage the process of updating document contents and retrieve document contents efficiently. Experiments are done to evaluate MAXDOR model. MAXDOR will be compared with other well-known models available in the literature(Tatarinov et al., 2002) and (Torsten et al., 2004) using total expected value of rebuilding XML document execution time and insertion of token execution time.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Storing Linked XML documents in Object-Relational DBMS

Currently, several researchers have proposed mapping both structure and constraints of XML documents to an object-relational database (ORDB). However these researches cannot be conducted because of the limited range of constraints in available object-relational DBMSs. We therefore propose mapping rules that are practicable in available technologies. Normally, an XML document is treated as a database so much data redundancy occurs. To solve this problem, we keep non-redundant data in several separate XML documents, link the data dispersed in these documents together by a mechanism called ‘rlink’ and then map this mechanism to ORDB. Finally we perform a case study in Oracle9i to illustrate the mapping of XML to ORDB according to our rules. Our contribution is that we find that mapping linked XML documents to traditional databases such as (O)RDB makes it easier to join several documents and to update several documents in one update command