2642886
Cache-Conscious Automata for XML Filtering
Hardware cache behavior is an important factor in the performance of memory-resident, data-intensive systems such as XML filtering engines. A key data structure in several recent XML filters is the automaton, which is used to represent the long-running XML queries in the main memory. In this paper, we study the cache performance of automaton-based XML filtering through analytical modeling and system measurement. Furthermore, we propose a cache-conscious automaton organization technique, called the hot buffer, to improve the locality of automaton state transitions. Our results show that 1) our cache performance model for XML filtering automata is highly accurate and 2) the hot buffer improves the cache performance as well as the overall performance of automaton-based XML filtering
42601258
On the Optimality of Holistic Algorithms for Twig Queries
Streaming XML documents has many emerging applications. However, in this paper, we show that the restrictions imposed by data streaming are too restrictive for processing twig queries – the core operation for XML query processing. Previous proposed algorithm TwigStack is an optimal algorithm for processing twig queries with only descendent edges over streams of nodes. The cause of the suboptimality of the TwigStack algorithm is the structurally recursions appearing in XML documents. We show that without relaxing the data streaming model, it is not possible to develop an optimal holistic algorithm for twig queries. Also the computation of the twig queries is not memory bounded. This motivates us to study two variations of the data streaming model: (1) offline sorting is allowed and the algorithm is allowed to select the correct nodes to be streamed and (2) multiple scans on the data streams are allowed. We show the lower bounds of the two variations.
3203090
What are real DTDs like?
DTDs have proved important in a variety of areas: transformations between XML and databases, XML storage, XML publishing, consistency analysis of XML specifications, typechecking, and optimization of XML queries. Much of this work depends on certain assumptions about DTDs, e.g., the absence of recursion and non-determinism. With this comes the need to justify these assumptions against DTDs in the real world. This paper surveys a number of DTDs collected from the Web, and provides statistics with respect to a variety of criteria commonly discussed in XML resesarch.
10441527
Efficient Support for Ordered XPath Processing in Tree-Unaware Commercial Relational Databases
In this paper, we present a novel ordered XPATH evaluation in treeunaware RDBMS. The novelties of our approach lies in the followings. (a) We propose a novel XML storage scheme which comprises only leaf nodes, their corresponding data values, order encodings and their root-to-leaf paths. (b) We propose an algorithm for mapping ordered XPATH queries into SQL queries over the storage scheme. (c) We propose an optimization technique that enforces all mapped SQL queries to be evaluated in a "left-to-right" join order. By employing these techniques, we show, through a comprehensive experiment, that our approach not only scales well but also performs better than some representative tree-unaware approaches on more than 65% of our benchmark queries with the highest observed gain factor being 1939. In addition, our approach reduces significantly the performance gap between tree-aware and tree-unaware approaches and even outperforms a state-of-the-art tree-aware approach for certain benchmark queries.
10012054
A development environment for customer-oriented Internet business: eBizBench
Abstract An important challenge in the age of Internet business is the proper alignment of customers’ needs with the business system. In order to improve an Internet business system according to customers’ needs continuously, reuse of design results is of particular importance. This paper proposes a development environment, called eBizBench, which provides support for this alignment and reusability. The eBizBench includes seven functions: (1) project management, (2) customer analysis, (3) value analysis, (4) web design, (5) implementation design, (6) repository management, and (7) repository. The eBizBench can help develop and maintain Internet business systems in a systematic fashion. The repository is useful for the conversion of design results among development environments. A real-life web site is illustrated to demonstrate the usefulness of the eBizBench.
38524318
Making Sense of Search Results by Automatic Web-page Classifications
This paper reports the development of a system for automatically organizing Internet web pages into meaningful categories. The aim of the system is to allow Internet users to find useful information in less time. The current problem with using the Internet is how to find the information that we need. With the explosive growth in the Internet, the information overload situation is getting worse. The proposed system automatically classifies web pages based on three types of information: (1) The system analyzes organizational information among web pages (inter-web-page relationship), such as an URL and links within a web page. (2) It analyzes the meta-web-page information such as data contained in META tags and formatting data of a web page. And (3), it analyzes web-page-content information such as keywords and phrases in the content of a web page. Our results show that combining all three types of information provides better accuracy.
7584097
An Adaptive Web Cache Access Predictor Using Neural Network
This paper presents a novel approach to successfully predict Web pages that are most likely to be re-accessed in a given period of time. We present the design of an intelligent predictor that can be implemented on a Web server to guide caching strategies. Our approach is adaptive and learns the changing access patterns of pages in a Web site. The core of our predictor is a neural network that uses a backpropagation learning rule. We present results of the application of this predictor on static data using log files; it can be extended to learn the distribution of live Web page access patterns. Our simulations show fast learning, uniformly good prediction, and up to 82% correct prediction for the following six months based on a one-day training data. This long-range prediction accuracy is attributed to the static structure of the test Web site.
2715830
Utilization-Based Admission Control for Scalable Real-Time Communication
We propose a utilization-based schedulability and admission control mechanism for distributed systems with workload aggregation to achieve scalability. We use the differentiated services (diffserv) architecture to describe and illustrate our approach. Scalability of admission control is achieved by determining off-line safe levels of server utilization. Scalability during the connection lifetimes is provided by the aggregation mechanisms (for example, class-based scheduling) provided by the diffserv architecture. Our evaluations show that our system's admission probabilities are very close to those of significantly more expensive approaches, which do not allow for workload aggregation. At the same time, admission control overhead during flow establishment is very low.
14865238
Adopting ontology to facilitate knowledge sharing
Ontology-enabled knowledge management experiences derived from a domain ontology development project at Intel Corporation are described and assessed.