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Very few research works have been done on XML security over relational databases despite that XML became the de facto standard for the data representation and exchange on the internet and a lot of XML documents are stored in RDBMS. In [14], the author proposed an access control model for schema-based storage of XML documents in relational storage and translating XML access control rules to relational access control rules. However, the proposed algorithms had performance drawbacks. In this paper, we will use the same access control model of [14] and try to overcome the drawbacks of [14] by proposing an efficient technique to store the XML access control rules in a relational storage of XML DTD. The mapping of the XML DTD to relational schema is proposed in [7]. We also propose an algorithm to translate XPath queries to SQL queries based on the mapping algorithm in [7].

TCP and UDP communication protocols are the most widely used transport methods for carrying out XML data messages between different services. XML data security is always a big concern especially when using internet cloud. Common XML encryption techniques encrypt part of private sections of the XML file as an entire block of text and apply these techniques directly on them. Man-in-the-Middle and Cryptanalysts can generate statistical information, tap, sniff, hack, inject and abuse XML data messages. The purpose of this study is to introduce architecture of new approach of exchanging XML data files between different Services in order to minimize the risk of any alteration, data loss, data abuse, data misuse of XML critical business data information during transmission; by implementing a vertical partitioning on XML files. Another aim is to create a virtual environment within internet cloud prior to data transmission in order to utilise the communication method and rise up the transmission performance along with resources utilisation and spreads the partitioned XML file (shredded) through several paths within multi agents that form a multipath virtual network. Virtualisation in cloud network infrastructure to take advantage of its scalability, operational efficiency, and control of data flow are considered in this architecture. A customized UDP Protocol in addition to a pack of modules in RIDX adds a reliable (Lossless) and Multicast data transmission to all nodes in a virtual cloud network. A comparative study has been made to measure the performance of the Real-time Interactive Data Exchange system (RIDX) using RIDX UDP protocol against standard TCP protocol. Starting from 4 nodes up to 10 nodes in the domain, the results showed an enhanced performance using RIDX architecture over the standard TCP protocol.

Many organizations today store their critical business information permanently in XML format. XML data can be managed using: XML-Enabled Database (XED) systems which convert and store XML files in traditional database systems; Native XML Database (NXD) systems which store XML data natively using three main storage technologies – text-based, model-based, and schema-based techniques; and Hybrid Database systems which are comprised of both XML-Enabled and Native XML database systems. NXDs are faster than other database technologies because there is no need to convert the format of the data prior to storage. No performance evaluation has been carried out to compare all three storage strategies, hence, this paper reports on the first attempt to evaluate all three storage strategies by using open source products to measure the response time taken for each of the database basic tasks such as database creation, dataset insertion, and data manipulation. The results of the evaluation show that the schema-based storage strategy: performs 3.5 times faster than the other two storage techniques in data insertion; shows very good performance in query processing on small and large datasets; performs 10.33 times faster than text-based, and 7.5 times faster than model-based storage techniques in query processing of large datasets.

Since the boom in new proposals on techniques for efficient querying of XML data is now over and the research world has shifted its attention toward new types of data formats, we believe that it is crucial to review what has been done in the area to help users choose an appropriate strategy and scientists exploit the contributions in new areas of data processing. The aim of this work is to provide a comprehensive study of the state-of-the-art of approaches for the structural querying of XML data. In particular, we start with a description of labeling schemas to capture the structure of the data and the respective storage strategies. Then we deal with the key part of every XML query processing: a twig query join, XML query algebras, optimizations of query plans, and selectivity estimation of XML queries. To the best of our knowledge, this is the first work that provides such a detailed description of XML query processing techniques that are related to structural aspects and that contains information about their theoretical and practical features as well as about their mutual compatibility and general usability.

Summary Domain-Specific Languages (DSLs) allow for the building of applications that ease the labour of both software engineers and domain experts thanks to the level of abstraction they provide. In cases where the domain is restricted to Client-Side Web Applications (CSWA), XML-based languages, frameworks and widgets are commonly combined in order to provide fast, robust and flexible solutions. This article presents an approach designed to create XML-based DSL solutions for CSWA that includes an evaluation engine, a programming model and a lightweight development environment. The approach is able to evaluate multiple XML-based DSL programs simultaneously to provide solutions to those Domain Specific Problems for CSWAs. To better demonstrate the capabilities and potential of this novel approach, we will employ a couple of case studies, namely Anisha and FeedPsi .

While the migration from DTD to XML Schema was driven by a need for increased expressivity and flexibility, the latter was also significantly more complex to use and understand. Whereas DTDs are characterized by their simplicity, XML Schema Documents are notoriously difficult. In this article, we introduce the XML specification language BonXai, which incorporates many features of XML Schema but is arguably almost as easy to use as DTDs. In brief, the latter is achieved by sacrificing the explicit use of types in favor of simple patterns expressing contexts for elements. The goal of BonXai is not to replace XML Schema but rather to provide a simpler alternative for users who want to go beyond the expressiveness and features of DTD but do not need the explicit use of types. Furthermore, XML Schema processing tools can be used as a back-end for BonXai, since BonXai can be automatically converted into XML Schema. A particularly strong point of BonXai is its solid foundation rooted in a decade of theoretical work around pattern-based schemas. We present a formal model for a core fragment of BonXai and the translation algorithms to and from a core fragment of XML Schema. We prove that BonXai and XML Schema can be converted back-and-forth on the level of tree languages and we formally study the size trade-offs between the two languages. We acknowledge the financial support of grant number MA 4938/2-1 from the Deutsche Forschungsgemeinschaft (Emmy Noether Nachwuchsgruppe). We further acknowledge the financial support of the Future and Emerging Technologies (FET) programme within the Seventh Framework Programme for Research of the European Commission, under the FET-Open grant agreement FOX, number FP7-ICT-233599.

Dealing with heterogeneous data underlying fuzzy XML databases is challenging for any task of document management and knowledge discovery, since the structural heterogeneity and uncertainty of the large number of XML data sources make it difficult to effectively answer the structured query, especially the tree-pattern query. To address this issue, we propose a novel framework for managing fuzzy XML queries in a heterogeneous environment in this paper. In particular, we devise a holistic algorithm for matching tree-patterns over heterogeneous fuzzy XML data. Our approach adopts a compact stack technique and generates the matches by one scan on the relevant data associated with the tree-pattern, which eliminates re-scanning unnecessary portions of XML documents and redundant intermediate results. Finally, a comprehensive experimental evaluation conducted on real and synthetic data sets is carried out to show the significance of our approach as a solution for querying heterogeneous data in fuzzy XML documents.

A new structure for streaming the XML data is proposed which guarantees confidentiality of the XML data over the wireless stream.An access mechanism is proposed to efficiently process XML queries over the encrypted XML stream. Recently, the use of XML for data broadcasting in mobile wireless networks has gained many attentions. One of the most essential requirements for such networks is data confidentiality. In order to secure XML data broadcast in mobile wireless networks, mobile clients should obey a set of access authorizations specified on the original XML document. In such environments, mobile clients can only access authorized parts of encrypted XML stream based on their access authorizations. Several indexing methods have been proposed in order to have selective access to XML data over the XML stream. However, these indexing methods cannot be used for encrypted XML data. In this paper, we define a new structure for XML stream which supports data confidentiality of XML data over the wireless broadcast channel. We also define an access mechanism for our proposed structure to efficiently process XML queries over the encrypted XML stream. The experimental results demonstrate that the use of our proposed structure and access mechanism for XML data broadcast efficiently disseminates XML data in mobile wireless networks.

Querying nested data has become one of the most challenging issues for retrieving desired information from the Web. Today diverse applications generate a tremendous amount of data in different formats. These data and information exchanged on the Web are commonly expressed as nested representation such as XML, JSON, etc. Unlike the traditional database system, they don't have a rigid schema. In general, the nested data is managed by storing data and its structures separately which significantly reduces the performance of data retrieving. Ensuring efficiency of processing queries which locates the exact positions of the elements has become a big challenging issue. There are different indexing structures which have been proposed in the literature to improve the performance of the query processing on the nested structure. Most of the past researches on nested structure concentrate on the structure alone. This paper proposes new index structure which combines siblings of the terminal nodes as one path which efficiently processes twig queries with less number of lookups and joins. The proposed approach is compared with some of the existing approaches. The results also show that they are processed with better performance compared to the existing ones.

In spite of its popularity, XML provides poor user experience and a lot of domain-specific languages can be improved by introducing custom, more humanfriendly notation. This paper presents an approach for design and development of the custom notation for existing XML-based language together with a translator between the new notation and XML. The approach supports iterative design of the language concrete syntax, allowing its modification based on users feedback. The translator is developed using a model-driven approach. It is based on explicit representation of language abstract syntax (metamodel) that can be augmented with mappings to both XML and the custom notation. We provide recommendations for application of the approach and demonstrate them on a case study of a language for definition of graphs.

The Extensible Markup Language (XML) data model has recently gained huge popularity because of its ability to represent a wide variety of structured (relational) and semi-structured (document) data. Several query languages have been proposed for the XML model, the most-widely used one is the XQuery. An important component of an XQuery is its XPath expression which retrieves a set of XML documents to be manipulated by the associated XQuery. An XPath expression can be of several types, among which are the containment queries. Traditional research of processing containment queries has concentrated on data retrieval from independent XML documents; not much research has been directed towards interlinked XML documents. This paper reviews this area of research and shows the adequacy and correctness of one of the reviewed algorithms when applied to independent XML documents. However, the direct application of this algorithm to process queries against interlinked XML documents is shown to generate incorrect results. To remedy such a situation, two new algorithms and the associated indexing structures are developed and shown to perform correctly in processing both independent and/or inter-linked XML documents. In addition, one of the new algorithms is shown to minimize the storage requirement of the intermediate lists generated throughout its execution and therefore improving further the algorithm's space and time performance.

Since XML has become a standard for information exchange over the Internet, more and more data are represented as XML. XML keyword search has been attracted a lot of interests because it provides a simple and user-friendly interface to query XML documents. This paper provides a survey on keyword search over XML document. We mainly focus on the topics of defining semantics for XML keyword search and the corresponding algorithms to find answers based on these semantics. We classify existing works for XML keyword search into three main types, which are tree-based approaches, graph-based approaches and semantics-based approaches. For each type of approaches, we further classify works into sub-classes and especially we summarize, make comparison and point out the relationships among sub-classes. In addition, for each type of approach, we point out the common problems they suffer

The multicore architecture has been the norm for all computing systems in recent years as it provides the CPU-level support of parallelism. However, existing algorithms for processing XML streams do not fully take advantage of the facility since they have not been devised to run in parallel. In this article, we propose several methods to parallelize the finite state automata (FSA)-based XML stream processing technique efficiently. We transform a large collection of XPath expressions into multiple FSA-based query indexes and then process XML streams in parallel by virtue of the index-level parallelism. Each core works only with its own query index so that no synchronization issue occurs while filtering XML streams with multiple path patterns given by users. We also present an in-memory MapReduce model that enables to process a large collection of twig pattern joins over XML streams simultaneously. Twig pattern joins in our approach are performed by multiple H/W threads in a shared and balanced way. Extensive experiments show that our algorithm outperforms conventional algorithms with an 8-core CPU by up to ten times for processing 10 million XPath expressions over XML streams.

The eXtensible Markup Language (XML) has been widely adopted in many financial institutions in their daily transactions. This adoption was due to the flexible nature of XML providing a common syntax for systems messaging in general and in financial messaging in specific. Excessive use of XML in financial transactions messaging created an aligned interest in security protocols integrated into XML solutions in order to protect exchanged XML messages in an efficient yet powerful mechanism. However, financial institutions (i.e. banks) perform large volume of transactions on daily basis which require securing XML messages on large scale. Securing large volume of messages will result performance and resource issues. Therefore, an approach is needed to secure specified portions of an XML document, syntax and processing rules for representing secured parts. In this research we have developed a smart approach for securing financial XML transactions using effective and intelligent fuzzy classification techniques. Our approach defines the process of classifying XML content using a set of fuzzy variables. Upon fuzzy classification phase, a unique value is assigned to a defined attribute named “Importance Level”. Assigned value indicates the data sensitivity for each XML tag. The research also defines the process of securing classified financial XML message content by performing element-wise XML encryption on selected parts defined in fuzzy classification phase. Element-wise encryption is performed using symmetric encryption using AES algorithm with different key sizes. Key size of 128-bit is being used on tags classified with “Medium” importance level; a key size of 256-bit is being used on tags classified with “High” importance level. An implementation has been performed on a real-life environment using online banking system in Jordan Ahli Bank one of the leading banks in Jordan to demonstrate its flexibility, feasibility, and efficiency. Our experimental results of the system verified tangible enhancements in encryption efficiency, processing-time reduction, and resulting XML message sizes. Finally, our proposed system was designed, developed, and evaluated using a live data extracted from an internet banking service in one of the leading banks in Jordan. The results obtained from our experiments are promising, showing that our model can provide an effective yet resilient support for financial systems to secure exchanged financial XML messages.

SAX can parse XML documents but cannot create them. In contrast, DOM can parse and create XML documents. This chapter introduces you to DOM.

As XML files are less redundant and readily reorganized, it is really difficult to design a XML watermarking scheme which can get a trade-off between robust and invisible. However, this trade-off can be achieved by the Zero-Watermark method. In this paper, two Zero-Watermark methods are designed and tested for XML documents. One is XSLT-related method which is designed with embedding extra codes in XSLT file to serve as sort of copyright function. Another uses the functional dependency of XML file as feature for Zero-Watermark. Experiment results show that both methods have good real-time performances. Experiment results show that Zero-Watermark algorithm with functional dependency can resist selection attacks, alteration attacks, reorganization attacks and compression attacks.

XML emerged as a de-facto standard for data representation and information exchange over the World Wide Web. By utilizing document object model (DOM), XML document can be viewed as XML DOM tree. Nodes of an XML tree are labeled to uniquely identify every node by following a labeling scheme. This paper proposes a method to efficiently identify the two structural relationships namely document order (DO) and sibling relationship that exist between the XML nodes using two secure labeling schemes specifically enhanced Dewey coding (EDC) and secure Dewey coding (SDC). These structural relationships influence the performance of XML queries so they need to be identified in efficient time. This paper implements the method to identify DO and sibling relationship using EDC and SDC labels for various real-time XML documents. Experiment results show the identification of DO and sibling relationship using SDC labels performs better than EDC labels for processing XML queries.

XML is a popular choice for development of domain-specific languages. In spite of its popularity, XML is a poor user interface and a lot of languages can be improved by introducing custom notation. This paper presents an approach for development of custom human-friendly notation for existing XML-based language together with a translator between the new notation and XML. This approach is based on explicit representation of language abstract syntax that can be decorated with mappings to both XML and the custom notation. The approach supports iterative design and development of the language concrete syntax, allowing its modification based on users feedback. Development process is demonstrated on a case study of language for definition of graphical user interface layout.

With the increasing of data at an incredible rate, the development of cloud computing technologies is of critical importance to the advances of researches. MapReduce is a widely adopted computing framework for data-intensive applications running on clusters. Traditional parallel XML parsing and indexing approaches are inadequate for processing large-scale XML datasets on clusters and; therefore, we propose an approach to exploit data parallelisms in XML processing using MapReduce in Hadoop. Our solution seamlessly integrates data storage, labeling, indexing, and parallel queries to process a massive amount of XML data. Specifically, we introduce an SDN labeling algorithm and a distributed hierarchical index using DHTs. More importantly, we design an advanced two phase MapReduce solution that is able to efficiently address the issues of labeling, indexing, and query processing on big XML data. The first MapReduce phase applies filtering, labeling, index building techniques, in which each DataNode performs elements labeling using a map function and a reduce function to merge and build indexes. In the second phase, local XML queries in multiple partitions are performed in parallel using index-table-enabled B-SLCA. Our experimental results show the efficiency and effectiveness of our proposed parallel XML data approach using MapReduce Framework.

The study is based on XISS(XML Indexing and Storage System) of Dietz’s Numbering Schema to determine the ancestor-descendant relationship. According to the results of research, this paper proposes an improved method of node encoding, realizes its indexing structure, and discusses its query path. Finally, the paper analyzes the property of this improved method.

MapReduce is a widely adopted computing framework for data-intensive applications running on clusters. This paper proposed an approach to exploit data parallelisms in XML processing using MapReduce in Hadoop. The authors' solution seamlessly integrates data storage, labeling, indexing, and parallel queries to process a massive amount of XML data. Specifically, the authors introduce an SDN labeling algorithm and a distributed hierarchical index using DHTs. More importantly, an advanced two-phase MapReduce solution are designed that is able to efficiently address the issues of labeling, indexing, and query processing on big XML data. The experimental results show the efficiency and effectiveness of the proposed parallel XML data approach using Hadoop.

XML-based publish/subscribe (pub/sub) systems have been receiving a great deal of attention from the academic community and the industry. This research focuses on efficient pub/sub systems and considers the devising of XML-based pub/sub systems from the perspective of subscription/query and publication message delivery. Existing research mainly focuses on the efficiency of XML publication message filtering algorithms. Not much research, however, has considered using the system or the communication model in the context of XML publication messages delivery. This paper presents innovative XML delivery techniques, the cross-layer model and the peer model; both techniques make use of publisher and customer edge brokers for efficient XML subscription aggregation and publication message delivery. The primary contribution of the proposed models is the reduction of the number of XML publication message filtering and XPath query aggregation operations performed in the conventional filter-based XML multicast model, which has a high computational overhead. The main idea is to store user subscriptions at customer and publisher edge brokers which are either directly connected or close to the subscribers and the publisher, respectively. We have performed a number of experiments within a controlled local area network (LAN) environment for demonstration of the basic concepts underlying the techniques and in the Amazon cloud environment that emulates the wide area network (WAN). Both the cross-layer and the peer models can reduce the end-to-end (E2E) delay in message delivery. For example, the results obtained from experiments in a LAN demonstrate several-fold performance improvement in E2E delay for both the cross-layer and the peer models compared to the conventional filter-based XML multicast model, and the results using the cloud show an improvement as high as 64% in E2E delay for the peer model over the multicast model.

Efficiently answering XML keyword queries has attracted much research effort in the last decade. The key factors resulting in the inefficiency of existing methods are the common-ancestor-repetition (CAR) and visiting-useless-nodes (VUN) problems. To address the CAR problem, we propose a generic top-down processing strategy to answer a given keyword query w.r.t. LCA/SLCA/ELCA semantics. By “ top-down ”, we mean that we visit all common ancestor (CA) nodes in a depth-first, left-to-right order; by “ generic ”, we mean that our method is independent of the query semantics. To address the VUN problem, we propose to use child nodes, rather than descendant nodes to test the satisfiability of a node $v$ w.r.t. the given semantics. We propose two algorithms that are based on either traditional inverted lists or our newly proposed LLists to improve the overall performance. We further propose several algorithms that are based on hash search to simplify the operation of finding CA nodes from all involved LLists. The experimental results verify the benefits of our methods according to various evaluation metrics.

The gap between storing data in relational databases and transferring data in form of XML has been closed e.g. by SQL/XML queries that generate XML data out of relational data sources. However, only few relational database systems support the evaluation of SQL/XML queries. And even in those systems supporting SQL/XML, the evaluation of such queries is quite slow compared to the evaluation of SQL queries. In this paper, we present S2CX, an approach that allows to efficiently evaluate SQL/XML queries on any relational database system, no matter whether it supports SQL/XML or not. As a result to an SQL/XML query, S2CX supports different output formats ranging from plain XML to different compressed XML representations including a succinct encoding of XML data, schema-aware compressed XML to grammar compressed XML. In many cases, S2CX produces compressed XML as a result to an SQL/XML query even faster than the evaluation of SQL/XML queries into non-compressed XML as provided by Oracle 11 g and by DB2. Furthermore, our approach to query evaluation scales better, i.e., the larger the dataset, the faster is our approach compared to SQL/XML query evaluation in Oracle 11 g and in DB2.

XML is a popular data definition language and is widely used for representation of arbitrary data structures. For queries on XML documents, XPath has commonly been used in many applications. The complexity of applying queries increases as the number of nodes in an XML document increases. Querying very large XML documents becomes really difficult when there is not enough computer memory to store and manipulate the whole tree data. The objective of this study is to develop an algorithm for querying very large XML trees in a distributed-memory environment. We split a large XML document into small chunks and parse the chunks to create special trees called partial trees. Then the query is executed in parallel on the partial trees. The results from the partial trees are concatenated to form the final query results for output. The algorithms were tested on a 16-node PC cluster, and the experiment results showed a speedup of a factor of 6 on 16 nodes.

A structured XML has been widely used to present services on various Web-services. The XML is also used for digital documents and digital signatures and for the representation of multimedia files in email systems. The XML document should be firstly parsed to access elements in the XML. The parsing is the most compute-instensive task in the use of XML documents. Most of the previous work has focused on hardware based XML parsers in order to improve parsing performance, while a little work has studied parsing techniques. We present the high performance parsing technique which can be used all of XML parsers and design hardware based XML parser using an FPGA. The proposed parsing technique uses element analyzers instead of the state machine and performs multibyte-based element matching. As a result, our parsing technique can reduce the number of clock cycles per byte(CPB) and does not need to require any preprocessing, such as loading XML data into memory. Compared to other parsers, our parser acheives 1.33~1.82 times improvement in the system performance. Therefore, the proposed parsing technique can process XML documents in real time and is suitable for applying to all of XML parsers.

Designed heterogeneous data sources for a hybrid version of the TPC-H enterprise.Developed hybrid LINQ queries over the relational and XML data sources.Evaluated the hybrid benchmark for loosely-coupled distributed data sources.Assessed query performance for two database products with various options. There are known benchmarks for the performance evaluation of relational and XML databases. However, there is an increasing demand for database applications that require access to heterogeneous loosely-coupled distributed data sources. This paper presents a hybrid benchmark based on TPC-H where the data sources are heterogeneous. Specifically, the paper describes the design of the relational and XML data sources as well as the query redesign in the LINQ query language, which supports queries over heterogeneous data sources. The results of a performance evaluation of the hybrid benchmark over various database products is included for untyped and typed XML with and without clearing the database cache.

JDBC, Java Database Connectivity, is a well-known and mature technology for a Java based client to connect to a relational database on a server, execute SQL commands, and process results of queries that reside on the server. Likewise, there are a few technologies such as XQJ, IBM Cognos to support such connectivity to XML. But these technologies require the whole document to be stored in memory before it can be processed. As a result, such technologies cannot handle large XML documents. Canonical Storage for XML (abbreviated CanStoreX and also Csx), is a suite of technologies that are under varying stages of development at our lab. CsxPagination paginates an XML document of any size and stores it in ready to consume pages that are loaded into main memory as needed. CsxDOM, is a Javabased DOM API for processing XML documents and CsxXQuery, built on the top of CsxDOM is for query of XML documents. Under the research reported here, we have developed CsxJBCX, Csx Java Based Connectivity for XML, built on the top of CanStoreX, CsxDOM, and CsxXQuery. It provides API to allow a client to access the XML on a server, submit an XQuery query for execution on the server, and use CsxDOM from the client to process the result residing on the server. We have also done some testing of JBCX on CyDIW (Cyclone Database Implementation Workbench) – a command-based software development environment in our lab.

International audience; In this paper we present Andromeda, a system for processing queries and updates on large XML documents. The system is based on the idea of statically and dynamically partitioning the input document, so as to distribute the computing load among the machines of a MapReduce cluster.

Definition XML access control refers to the practice of limiting access to (parts of) XML data to only authorized users. Similar to access control over other types of data and resources, XML access control is centered around two key problems: (i) the development of formal models for the specification of access control policies over XML data; and (ii) techniques for efficient enforcement of access control policies over XML data.

This chapter will clearly show the need for better mapping techniques for Relational Database (RDB) all the way to Resource Description Framework (RDF). This includes coverage of each data model limitations and benefits for getting better results. Here, each form of data being transform has its own importance in the field of data science. As RDB is well known back end storage for information used to many kinds of applications; especially the web, desktop, remote, embedded, and network-based applications. Whereas, EXtensible Markup Language (XML) in the well-known standard for data for transferring among all computer related resources regardless of their type, shape, place, capability and capacity due to its form is in application understandable form. Finally, semantically enriched and simple of available in Semantic Web is RDF. This comes handy when with the use of linked data to get intelligent inference better and efficient. Multiple Algorithms are built to support this system experiments and proving its true nature of the study.

Web-services employ XML that is the well-formed structure as a de-facto standard to represent data. SOAP or REST is one of the representative web-services using XML based massage passing systems. The XML parser can be divided into event driven and DOM tree. A streaming parser as an event driven is widely used for high-speed parsing. Since the streaming parser processes XML documents in sequence, they have any limitation to improve system performance. In order to improve speed of streaming XML parser, we present multibyte based streaming XML hardware parser using the element analyzer instead of the state machine. Compared to other parsers, the proposed MStreXHP can achieve about 2.72 times improvement in the number of clock cycles to be consumed in comparison of characters and sustain about 7.8Gbps throughput. Therefore, our MStreXHP is desirable for the streaming XML hardware parser on high-performance systems.

Web services are built on XML. They use XML for describing the service interface, they use XML for message exchange and the WS- $^*$ protocols that provide addressing, security and reliable messaging also use XML. This burdens the communication with a large response time overhead compared to binary distributed communications like CORBA or RMI. Therefore, it is important to know how to design the interface of a web service so we can minimize the communication overhead. In this paper we propose a performance model with which the response time overhead of web services with arbitrary interfaces can be predicted if the coefficients of the model are calculated from some simple measurements for the given set of test cases. The paper shows the measurement results for two web service frameworks and also gives a detailed description of the performance model.

Tuple extraction from streaming XML should be cost effective for real-time query evaluation. Recently, StreamTX exhibits a good performance in terms of both running time and memory usage to support the tuple extraction queries for streaming XML. However, we empirically observe that StreamTX incurs computational overhead unnecessarily, since it builds on TwigStack , an XML query processing algorithm originally developed for stored XML. In this paper, we first design a non-recursive XQStream algorithm to handle inefficient recursive calls of StreamTX . Subsequently, we extend the basic XQStream by incorporating two novel schemes: (1) the relational pointer to efficiently and effectively evaluate the structural relationship of elements, and (2) the pattern reuse to reduce redundant path evaluations for pattern matching. The performance evaluation on various datasets provides new empirical findings. First, XQStream++ , which incorporates the relational pointer and the pattern reuse scheme into XQStream , significantly outperforms the state-of-the-art algorithms in running time with a small, nearly constant memory usage. Second, the most recently released XQuery engines outperform StreamTX in running time.

XML has become the de facto standard for data exchange and transformation on the World Wide Web and is widely used in many applications of various fields, so it is urgent to develop some efficient methods to manage, store, query, and update XML data. There are two main methods to do this: the first method is a native approach which uses native XML databases to store XML data, and the second method use other mature commercial databases approaches to store and manage XML data considering the advantages of mature technologies of the commercial databases, especially use relational databases to store, query, and update XML data. For relational databases approach, although it can take advantage of mature technologies of relational databases, it needs to map XML data to relational data. In this paper, we research the problem of how to store XML data so that storing and updating of original XML data can be efficient than relational approach. We proposed a method to store XML data into linked lists with inverted index, in which the relationships between nodes of XML data tree are preserved by the links in linked lists. Inverted index are created for linked lists for efficiently querying and updating XML data tree. Two kinds of updates are considered including inserting a new node in or deleted an existed old node from XML data tree. Theoretical analysis of our algorithms shows that the methods proposed in the paper are efficient.

Compiling documents in extensible markup language (XML) plays an important role in accessing data services. An efficient query service should be based on a skillful representation that can support query diversification and solve ambiguity in order to improve high-precision search capabilities. However, to the best of our knowledge, research on query diversification, target hierarchical level and the problem of ambiguity is insufficient. In this study we aimed to solve these problems so that the results are able not only to satisfy query diversification, but also to offer better precision compared with the existing twig join algorithms. An extended twig join Swift (TJSwift) associated with adjacent linked lists for the provision of efficient XML query services is also proposed, whereby queries can be versatile in terms of predicates. It can completely preserve hierarchical information; in addition, the new index generated from XML is used to save semantic information.

XML has become the dominant standard for data exchange and representation on the Web. The Relational Database (RDB) possesses is widely used as a storage and retrieval medium in the business field. With the expanding utilization of XML data on the Web, the size of this data type has increased rapidly, and more complicated queries are issued by users through this data. This expansion has prompted numerous researchers to propose various approaches in managing XML data through RDB. In this study, the most cited and the latest model-mapping approaches are reviewed in terms of the description, the technique used and the RDB schema produced using each approach. The limitations of these approaches are discussed, in terms of the storage space and query response time. At the end of this study, a solution to these limitations is proposed. It is hoped that this paper will give some insight into storing XML documents in RDB schema and contribute to the XML community.

Aiming at the fact that traditional cache replacement strategy lacks pertinence to the semantic cache in the process of extensible markup language (XML) algebra query, a replacement strategy based on the semantic cache contribution value is proposed. First, pattern matching rules for XML algebra query and semantic caches are given. Second, the method of calculating the semantic cache contribution value is proposed. In XML documents with four different sizes, the experimental results of time efficiency show that this strategy supports environment of the XML algebra query and it has better time efficiency than both least frequency used (LFU) and least recently used (LRU).

A significant amount of data on the Web is in the XML format or may easily be converted to XML or to its variations. XML is still the most appropriate language for data interchange and serialization. In this paper, a new framework which can integrate any heterogeneous XML data sources is presented. Each data source is translated into semantically meaningful regular expressions without changing original data source. Proposed framework has two major phases for data preparation. In the first phase, each data source is processed to obtain regular expressions which accommodate with the design choices that made in target by utilizing known global semantic vocabulary as an input. The second phase combines these regular expressions to get a global schema by preserving the original source data. A regular expression generator tool which produces regular expressions by regarding vocabulary and an integrator tool box which integrates and processes regular expressions, are also introduced.

Recently, the sizes of XML documents have rapidly been increasing. Distributed XML is a novel form of XML document, in which an XML document is partitioned into fragments and managed separately in plural sites. Distributed XML documents can often be managed more easily than a single large document, due to geographical and/or administrative factors. In this paper, we propose a method for performing XSLT transformation efficiently for distributed XML documents. We assume that the expressive power of XSLT is restricted to an extended version of unranked top-down tree transducer. Our basic strategy is to transform all the XML fragments in parallel. We implemented our method in Ruby and made evaluation experiments. This result suggests that our method is more efficient than a centralized approach.

The verbose nature of XML has been mulled over again and again and many compression techniques for XML data have been excogitated over the years. Some of the techniques incorporate support for querying the XML database in its compressed format while others have to be decompressed before they can be queried. XML compression in which querying is directly supported instantaneously with no compromise over time is forced to compromise over space. In this paper, we propose the compressor, QRFXFreeze, which not only reduces the space of storage but also supports efficient querying. The compressor does this without decompressing the compressed XML file. The compressor supports all kinds of XML documents along with insert, update, and delete operations. The forte of QRFXFreeze is that the textual data are semantically compressed and are indexed to reduce the querying time. Experimental results show that the proposed compressor performs much better than other well-known compressors.