A Clustering-based Scheme for Labeling XML Trees

Lecture Notes in Computer Science, 2001

Bohannon et al. claim that XML is becoming the predominant data exchange format in a variety of application domains. Altinel and Franklin hold that the advent of XML as a standard for information exchange and the development of query languages for XML data enable the development of more sophisticated filtering mechanisms that take structure information into account. Shanmugasundaram et al. develop algorithms and implement a prototype system that converts XML documents to relational tuples, translates semi-structured queries over XML documents to SQL queries over tables, and converts the results to XML. Quint and Vatton review the main innovations of XML and consider their impact on the editing techniques for structured documents. Bohannon et al. claim that XML is becoming the predominant data exchange format in a variety of application domains:

2008

In this paper, we propose a new structure-based approach, called Xregion, to storing XML data in relational databases. Our approach first partitions an XML document into several disjoint regions according to the cardinality of element nodes, and then maps these regions into separate relations. The experimental results demonstrate that the proposed approach dramatically improves the performance of queries on the XML data over the generic mapping approaches.

2002

In this paper we will present different storage approaches for XML documents, the document centered, the data and the structure centered approach. We will then focus on the structure centered approach and will introduce an abstract view on XML documents using tree graphs. To make these tree graphs persistent different storage techniques are mentioned and evaluated concerning the creation and retrieval of complete documents. Measurement results are shown and shortly discussed for creation and retrieval of different (complete) XML documents. Moreover we will shortly introduce the partial mapping extension, which helps to optimize the generic structure based storage approach for specific documents whose structure is known in advance. The results presented come from the ongoing implementation of a high performance generic document server with an analytic decision support agent.

Journal of Systems and Software, 2009

In this paper, we propose an efficient encoding and labeling scheme for XML, called EXEL, which is a variant of the region labeling scheme using ordinal and insertfriendly bit strings. We devise a binary encoding method to generate the ordinal bit strings, and an algorithm to make a new bit string inserted between bit strings without any influences on the order of preexisting bit strings. These binary encoding method and bit string insertion algorithm are the bases of the efficient query processing and the complete avoidance of re-labeling for updates. We present query processing and update processing methods based on EXEL. In addition, the Stack-Tree-Desc algorithm is used for an efficient structural join, and the String B-tree indexing is utilized to improve the join performance. Finally, the experimental results show that EXEL enables complete avoidance of re-labeling for updates while providing fairly reasonable query processing performance.

Knowledge-Based Systems, 2011

With the rapid emergence of XML as a data exchange standard over the Web, storing and querying XML data have become critical issues. The two main approaches to storing XML data are (1) to employ traditional storage such as relational database, object-oriented database and so on, and (2) to create an XMLspecific native storage. The storage representation affects the efficiency of query processing. In this paper, firstly, we review the two approaches for storing XML data. Secondly, we review various query optimization techniques such as indexing, labeling and join algorithms to enhance query processing in both approaches. Next, we suggest an indexing classification scheme and discuss some of the current trends in indexing methods, which indicate a clear shift towards hybrid indexing.

Journal of Software, 2015

Due to Its simplicity, its flexibility and its expansion possibilities, XML can be adapted to multiple domains. Its self-described structure and nesting, allows XML to become the dominant standard for storing and transferring data through the World Wide Web. In addition the relational database systems are mature and extremely powerful. Therefore, many researches have been done to propose an efficient approach to store and query an XML document in Relational Database. In this paper we present a new approach to store and query an XML document using relational databases, which decompose an XML document into three tables without using any XML schema or DTD. Our approach supports efficiently the structural modifications to the XML tree, and achieves lower storage consumption. Also, we propose two powerful algorithms for mapping XML data to relational databases and from relational database to XML data.

Proceedings of the 3rd international workshop on Web …, 2001

XML is an emerging standard for the representation and exchange of Internet data. Along with document type definition (DTD), XML permits the execution of a collection of queries, using XPath to identify data in XML documents. In this paper we examine how XML data can be stored and queried using a standard relational database management system (RDBMS). For this, we propose a technique for automatic mapping from an XML document to relations within the RDBMS. We demonstrate that our novel approach preserves the nested structure of the XML documents. By hiding database details we devise a seamless, transparent framework for user access to XML data. In order to achieve this, we propose a novel mechanism for translating an XPath query into an SQL statement. Furthermore, we propose efficient techniques for the construction of an XML document on the fly from the result set of the SQL statement. We also present findings in terms of query response time on the comparative performance of different techniques for the construction of an XML document on the fly.

International Journal of Web Engineering and Technology, 2004

With the increasing amount of XML used in web applications for representing and exchanging information, researchers have proposed different methods of using relational database to store and manage XML data. The model-mapping methods do not require DTD so that fixed database schemas can be used. In this paper, we present a new model-mapping method called INode*. This method is based on a numbering scheme for mapping XML data into relational databases. It enables quick retrieval of ancestor-descendant relationships between elements in XML by simple calculations. Experiments show that INode* can reduce the storage requirement while having a better query performance in comparison to several other model-mapping methods.

Proceedings of the International Conference on Semantic Web and Web Services, 2006

Abstract-Representing XML data in terms of the rows and columns of a relational table is quite inefficient. Similarly, object-oriented databases cater for storage of objects but lack fast access. In these cases, a better technique is required to speedup representation and retrieval of hierarchical data in relational databases. This paper presents XMLEase, a new access-and store-efficient technique to keep XML data in relational databases. XMLEase keeps data node together with its successors down to a pre-defined level of hierarchy. ...

Lecture Notes in Computer Science, 2009

Due to the growing popularity of XML as a data exchange and storage format, the need to develop efficient techniques for storing and querying XML documents has emerged. A common approach to achieve this is to use labeling techniques. However, their main problem is that they either do not support updating XML data dynamically or impose huge storage requirements. On the other hand, with the verbosity and redundancy problem of XML, which can lead to increased cost for processing XML documents, compaction of XML documents has become an increasingly important research issue. In this paper, we propose an approach called CXDLS combining the strengths of both, labeling and compaction techniques. Our approach exploits repetitive consecutive subtrees and tags for compacting the structure of XML documents by taking advantage of the ORDPATH labeling scheme. In addition it stores the compacted structure and the data values separately. Using our proposed approach, it is possible to support efficient query and update processing on compacted XML documents and to reduce storage space dramatically. Results of a comprehensive performance study are provided to show the advantages of CXDLS.