bluuebunny/crossref_metadata_2025 huggingface dataset:
Efficient transparent application recovery in client-server information systems
Authors: Lomet David , Weikum Gerhard
Published: November 2005

Database systems recover persistent data, providing high database availability. However, database applications, typically residing on client or “middle-tier” application-server machines, may lose work because of a server failure. This prevents the masking of server failures from the human user and substantially degrades application availability. This paper aims to enable high application availability with an integrated method for database server recovery
and
transparent application recovery in a client-server system. The approach, based on application message logging, is similar to earlier work on distributed system fault tolerance. However, we exploit advanced database logging and recovery techniques and request/reply messaging properties to significantly improve efficiency. Forced log I/Os, frequently required by other methods, are usually avoided. Restart time, for both failed server and failed client, is reduced by checkpointing and log truncation. Our method ensures that a server can recover independently of clients. A client may reduce logging overhead in return for dependency on server availability during client restart.
Next generation database systems won't work without semantics! (panel)
Authors: Mylopoulos John
Published: November 2005

In the late '70s, while second generation DBMS products and technologies were entering the market, there was significant research activity whose aim was to make greater use of semantic information in database systems. The focus of that research was primarily on semantic data models and data modelling, including semantic query processing and integrity checking. However, few if any of the results of these efforts found their way in database technologies of the day, or database management practices. Instead, semantic issues were delegated to early phases of information system development (including requirements analysis and design), as well as application development.

Today's database system technologies perform admirably well with semantically trivial operations and representations. At the same time, these technologies are being challenged in virtually every area of data management, with new applications which demand ways of dealing more explicitly with the meaning of the data being managed. For example, interoperation between applications requires that the underlying databases interoperate
meaningfully
. This currently requires a mammoth manual reverse engineering effort that simply cannot be sustained or funded by any large organization. The same applies to data warehouses, since they too require the correct semantic merging of data from semantically diverse sources. Errors in merging these sources can lead to significant problems of interpretation and potentially of the functions that the warehouse is designed to deliver. The effectiveness of database technologies to web-related information gathering and management applications is likewise limited by the degree to which they can accommodate semantics of the information being sought. Along the same lines, the emergence of organizational knowledge management as the next major application of computing in organizations clearly offers a tremendous opportunity for database technologies. But, again, this opportunity begs the question whether such technologies can succeed if they continue to ignore semantic issues.

In summary, semantic issues were put aside by database technologies of the past. However, the database application challenges of the '90s seem to demand solutions to precisely such issues today. This panel intends to examine these long standing research issues on database semantics and their failures to penetrate database technologies. The discussion will also review emerging application areas and their need for mechanisms that deal with data semantics. Finally, the panelists will comment on relevant research tasks that need to be addressed in this long-ignored area of database modeling, management, access, and processing.
SAP R/3 (tutorial)
Authors: Kemper Alfons , Kossmann Donald , Matthes Florian
Published: November 2005

Many database applications in the real world are no longer built on top of a stand-alone database system. Rather, generic (standard) application systems are employed in which the database system is one integrated component. SAP is the market leader for integrated business administration systems, and its SAP R/3 product is a comprehensive software system which integrates modules for finance, material management, sales and distribution, etc. From an architectural point of view, SAP R/3 is a client/server application system with a relational database system as back-end. SAP supports a choice between a variety of commercial relational database products.
Microsoft universal data access platform
Authors: Blakeley José A. , Pizzo Michael J.
Published: November 2005

Microsoft Universal Data Access defines a platform for developing multi-tier enterprise applications that require efficient access to diverse relational or non-relational data sources across intranets or the Internet. Universal Data Access consists of a collection of software components that interact with each other using system-level interfaces defined by OLE DB and providing an application-level data access model called ActiveX Data Objects (ADO). This talk provides an overview of the platform.
Database systems management and Oracle8
Authors: Doherty C. Gregory
Published: November 2005

Oracle's corporate mission is to enable the Information Age through
network computing
, a vision of broader access to information for all and the empowerment and increased productivity that can result. The technology implications of the network computing vision are ubiquitous access via low-cost appliances to smaller numbers of larger databases, accessed via professionally managed networks compliant with open internetworking protocols. The latest release of the Oracle data server, Oracle8, provides new technology for management of very large databases containing rich and user-defined data types, and is continuing to evolve to make it economically beneficial to store all forms of digital information in a database.
50,000 users on an Oracle8 universal server database
Authors: Lahiri Tirthankar , Joshi Ashok , Jasuja Amit , Chatterjee Sumanta
Published: November 2005

In this paper, we describe the Oracle Large User Population Demonstration and highlight the scalability mechanisms in the Oracle8 Universal Data Server which make it possible to support as many as 50,000 concurrent users on a single Oracle8 database without any middle-tier TP-monitor software. Supporting such large user populations requires many mechanisms for high concurrency and throughput. Algorithms in all areas of the server ranging from process and buffer management to SQL compilation and execution must be designed to be highly scalable. Efficient resource sharing mechanisms are required to prevent server-side resource requirements from growing unboundedly with the number of users. Parallel execution across multiple systems is necessary to allow user-population and throughput to scale beyond the restrictions of a single system. In addition to scalability, mechanisms for high availability, ease-of-use, and rich functionality are necessary for supporting complex user applications typical of realistic workloads. All mechanisms must be portable to a wide variety of installations ranging from desk-top systems to large scale enterprise servers and to a wide variety of operating systems.
About Quark Digital Media System
Authors: Aulakh Kamar
Published: November 2005

In this paper, we describe the Oracle Large User Population Demonstration and highlight the scalability mechanisms in the Oracle8 Universal Data Server which make it possible to support as many as 50,000 concurrent users on a single Oracle8 database without any middle-tier TP-monitor software. Supporting such large user populations requires many mechanisms for high concurrency and throughput. Algorithms in all areas of the server ranging from process and buffer management to SQL compilation and execution must be designed to be highly scalable. Efficient resource sharing mechanisms are required to prevent server-side resource requirements from growing unboundedly with the number of users. Parallel execution across multiple systems is necessary to allow user-population and throughput to scale beyond the restrictions of a single system. In addition to scalability, mechanisms for high availability, ease-of-use, and rich functionality are necessary for supporting complex user applications typical of realistic workloads. All mechanisms must be portable to a wide variety of installations ranging from desk-top systems to large scale enterprise servers and to a wide variety of operating systems.
FileNet integrated document management database usage and issues
Authors: Whelan Daniel S.
Published: November 2005

The FileNet Integrated Document Management (IDM) products consists of a family of client applications and Imaging and Electronic Document Management (EDM) services. These services provide robust facilities for document creation, update, and deletion along with document search capabilities. Document properties are stored in an underlying relational database (RDBMS); document content is stored in files or in a specialized optical disk hierarchical storage manager. FileNet Corporation's Visual WorkFlo® and Ensemble® workflow products can be utilized in conjunction with FileNet's IDM technologies to automate production and ad hoc business processes respectively.

This talk will discuss how Integrated Document Management requirements affect an IDM system's usage of a RDBMS. Some of the areas to be discussed include:
Free parallel data mining
Authors: Li Bin , Shasha Dennis
Published: November 2005

Data mining is computationally expensive. Since the benefits of data mining results are unpredictable, organizations may not be willing to buy new hardware for that purpose. We will present a system that enables data mining applications to run in parallel on networks of workstations in a fault-tolerant manner. We will describe our parallelization of a combinatorial pattern discovery algorithm and a classification tree algorithm. We will demonstrate the effectiveness of our system with two real applications: discovering active motifs in protein sequences and predicting foreign exchange rate movement.
FlowBack
Authors: Kiepuszewski Bartek , Muhlberger Ralf , Orlowska Maria E.
Published: November 2005

The Distributed Systems Technology Centre (DSTC) framework for workflow specification, verification and management captures workflows transaction-like behavior for long lasting processes. FlowBack is an advanced prototype functionally enhancing an existing workflow management system by providing process backward recovery. It is based on extensive theoretical research ([3],[4],[5],[6],[8],[9]), and its architecture and construction assumptions are product independent. FlowBack clearly demonstrates the extent to which generic backward recovery can be automated and system supported. The provision of a solution for handling exceptional business process behavior requiring backward recovery makes workflow solutions more suitable for a large class of applications, therefore opening up new dimensions within the market. For the demonstration purpose, FlowBack operates with IBM FlowMark, one of the leading workflow products.
Ariadne
Authors: Ambite José Luis , Ashish Naveen , Barish Greg , Knoblock Craig A. , Minton Steven , Modi Pragnesh J. , Muslea Ion , Philpot Andrew , Tejada Sheila
Published: November 2005

The Web is based on a browsing paradigm that makes it difficult to retrieve and integrate data from multiple sites. Today, the only way to achieve this integration is by building specialized applications, which are time-consuming to develop and difficult to maintain. We are addressing this problem by creating the technology and tools for rapidly constructing information mediators that extract, query, and integrate data from web sources. The resulting system, called Ariadne, makes it feasible to rapidly build information mediators that access existing web sources.
User-oriented smart-cache for the Web
Authors: Lacroix Zoé , Sahuguet Arnaud , Chandrasekar Raman
Published: November 2005

Standard database approaches to querying information on the Web focus on the source(s) and provide a query language based on a given predefined organization (schema) of the data: this is the
source-driven
approach. However, can the Web be seen as a standard database? There is no super-user in charge of monitoring the source(s) (the data is constantly updated), there is no homogeneous structure (no common explicit structure thus), the Web itself never stops growing, etc. For these reasons, we believe that the source-driven standard approach is not suitable to the Web.

As an alternative, we propose a
user-oriented
approach based on the idea that the schema is a posteriori expressed by the user's needs when asking a query. Given a user query, AKIRA (Agentive Knowledge-based Information Retrieval Architecture) [6] extracts a
target structure
(structure expressed in the query) and uses standard information retrieval and filtering techniques to access potentially relevant documents.

The user-oriented paradigm means that the structure through which the data is viewed does not come from the source but is extracted from the user query. When a user asks a query, the relevant information is retrieved from the Web and stored as is in a cache. Then the information is extracted from the raw data using computational linguistic techniques. The AKIRA cache (
smart-cache
) represents these extracted layers of meta-information on top of the raw data. The smart-cache is an object-oriented database whose schema is inferred from the user's target structure. It is designed on demand through a library of concepts that can be assembled together to match concepts and meta-concepts required in the user's query. The smart cache can be seen as a
view
of the Web.

To the best of our knowledge, AKIRA is the only system that uses information retrieval and extraction integrated with database techniques to provide maximum flexibility to the user and offer transparent access to the content of Web documents.
Xmas
Authors: Park Jang Ho , Kwon Yong Sik , Kim Ki Hong , Lee Sang Ho , Park Byoung Dae , Cha Sang Kyun
Published: November 2005

Xmas is an extensible main-memory storage system for high-performance embedded database applications. Xmas not only provides the core functionality of DBMS, such as data persistence, crash recovery, and concurrency control, but also pursues an extensible architecture to meet the requirements from various application areas. One crucial aspect of such extensibility is that an application developer can compose application-specific, high-level operations with a basic set of operations provided by the system. Called composite actions in Xmas, these operations are processed by a customized Xmas server with minimum interaction with application processes, thus improving the overall performance. This paper first presents the architecture and functionality of Xmas, and then demonstrates a simulation of mobile communication service.
MultiMediaMiner
Authors: Zaïane Osmar R. , Han Jiawei , Li Ze-Nian , Chee Sonny H. , Chiang Jenny Y.
Published: November 2005

Multimedia data mining is the mining of high-level multimedia information and knowledge from large multimedia databases. A multimedia data mining system prototype, MultiMediaMiner, has been designed and developed. It includes the construction of a multimedia data cube which facilitates multiple dimensional analysis of multimedia data, primarily based on visual content, and the mining of multiple kinds of knowledge, including
summarization, comparison, classification, association
, and
clustering
.
DTL's DataSpot
Authors: Dar Shaul , Entin Gadi , Geva Shai , Palmon Eran
Published: November 2005

DTL's DataSpot is an advanced, programming-free tool that lets Web designers and database developers automatically publish their databases for Web browser access. DataSpot enables non-technical end users to explore a database using free-form plain language queries combined with hypertext navigation, in a fashion similar to using search engines such as Alta Vista to search text files on the Internet.

DataSpot is based on a novel representation of data in the form of a schema-less semi-structured graph called a Web View. The DataSpot Publisher takes one or more possibly heterogeneous databases, predefined knowledge banks such as a thesaurus, and user-defined associations, and creates the Web View. The DataSpot Search Server, which connects to any standard HTTP server, performs searches and navigation against the Web View, generating dynamic HTML pages that are returned to the user. The presentation and navigation of answers are controlled by templates that can be modified by the data provider.

The DataSpot product has been successfully deployed in diverse Internet and Intranet application areas, including electronic catalogs, yellow pages, classified ads, help desks and finance.
Algebraic change propagation for semijoin and outerjoin queries
Authors: Griffin Timothy , Kumar Bharat
Published: November 2005

Many interesting examples in view maintenance involve semijoin and outerjoin queries. In this paper we develop algebraic change propagation algorithms for the following operators: semijoin, anti-semijoin, left outerjoin, right outerjoin, and full outerjoin.
Fast algorithms for projected clustering
Authors: Aggarwal Charu C. , Wolf Joel L. , Yu Philip S. , Procopiuc Cecilia , Park Jong Soo
Published: November 2005

The clustering problem is well known in the database literature for its numerous applications in problems such as customer segmentation, classification and trend analysis. Unfortunately, all known algorithms tend to break down in high dimensional spaces because of the inherent sparsity of the points. In such high dimensional spaces not all dimensions may be relevant to a given cluster. One way of handling this is to pick the closely correlated dimensions and find clusters in the corresponding subspace. Traditional feature selection algorithms attempt to achieve this. The weakness of this approach is that in typical high dimensional data mining applications different sets of points may cluster better for different subsets of dimensions. The number of dimensions in each such cluster-specific subspace may also vary. Hence, it may be impossible to find a single small subset of dimensions for all the clusters. We therefore discuss a generalization of the clustering problem, referred to as the
projected clustering problem
, in which the subsets of dimensions selected are specific to the clusters themselves. We develop an algorithmic framework for solving the projected clustering problem, and test its performance on synthetic data.
Querying network directories
Authors: Jagadish H. V. , Lakshmanan Laks V. S. , Milo Tova , Srivastava Divesh , Vista Dimitra
Published: November 2005

Heirarchically structured directories have recently proliferated with the growth of the Internet, and are being used to store not only address books and contact information for people, but also personal profiles, network resource information, and network and service policies. These systems provide a means for managing scale and heterogeneity, while allowing for conceptual unity and autonomy across multiple directory servers in the network, in a way for superior to what conventional relational or object-oriented databases offer. Yet, in deployed systems today, much of the data is modeled in an ad hoc manner, and many of the more sophisticated “queries” involve navigational access.

In this paper, we develop the core of a formal data model for network directories, and propose a sequence of efficiently computable query languages with increasing expressive power. The directory data model can naturally represent rich forms of heterogeneity exhibited in the real world. Answers to queries expressible in our query languages can exhibit the same kinds of heterogeneity. We present external memory algorithms for the evaluation of queries posed in our directory query languages, and prove the efficiency of each algorithm in terms of its I/O complexity. Our data model and query languages share the flexibility and utility of the recent proposals for semi-structured data models, while at the same time effectively addressing the specific needs of network directory applications, which we demonstrate by means of a representative real-life example.
Self-tuning histograms
Authors: Aboulnaga Ashraf , Chaudhuri Surajit
Published: November 2005

In this paper, we introduce self-tuning histograms. Although similar in structure to traditional histograms, these histograms infer data distributions not by examining the data or a sample thereof, but by using feedback from the query execution engine about the actual selectivity of range selection operators to progressively refine the histogram. Since the cost of building and maintaining self-tuning histograms is independent of the data size, self-tuning histograms provide a remarkably inexpensive way to construct histograms for large data sets with little up-front costs. Self-tuning histograms are particularly attractive as an alternative to multi-dimensional traditional histograms that capture dependencies between attributes but are prohibitively expensive to build and maintain. In this paper, we describe the techniques for initializing and refining self-tuning histograms. Our experimental results show that self-tuning histograms provide a low-cost alternative to traditional multi-dimensional histograms with little loss of accuracy for data distributions with low to moderate skew.
An adaptive query execution system for data integration
Authors: Ives Zachary G. , Florescu Daniela , Friedman Marc , Levy Alon , Weld Daniel S.
Published: November 2005

Query processing in data integration occurs over network-bound, autonomous data sources. This requires extensions to traditional optimization and execution techniques for three reasons: there is an absence of quality statistics about the data, data transfer rates are unpredictable and bursty, and slow or unavailable data sources can often be replaced by overlapping or mirrored sources. This paper presents the Tukwila data integration system, designed to support adaptivity at its core using a two-pronged approach. Interleaved planning and execution with partial optimization allows Tukwila to quickly recover from decisions based on inaccurate estimates. During execution, Tukwila uses adaptive query operators such as the double pipelined hash join, which produces answers quickly, and the dynamic collector, which robustly and efficiently computes unions across overlapping data sources. We demonstrate that the Tukwila architecture extends previous innovations in adaptive execution (such as query scrambling, mid-execution re-optimization, and choose nodes), and we present experimental evidence that our techniques result in behavior desirable for a data integration system.
Query optimization in the presence of limited access patterns
Authors: Florescu Daniela , Levy Alon , Manolescu Ioana , Suciu Dan
Published: November 2005

We consider the problem of query optimization in the presence of limitations on access patterns to the data (i.e., when one must provide values for one of the attributes of a relation in order to obtain tuples). We show that in the presence of limited access patterns we must search a space of
annotated query plans
, where the annotations describe the inputs that must be given to the plan. We describe a theoretical and experimental analysis of the resulting search space and a novel query optimization algorithm that is designed to perform well under the different conditions that may arise. The algorithm searches the set of annotated query plans, pruning invalid and non-viable plans as early as possible in the search space, and it also uses a best-first search strategy in order to produce a first complete plan early in the search. We describe experiments to illustrate the performance of our algorithm.
DynaMat
Authors: Kotidis Yannis , Roussopoulos Nick
Published: November 2005

Pre-computation and materialization of views with aggregate functions is a common technique in Data Warehouses. Due to the complex structure of the warehouse and the different profiles of the users who submit queries, there is need for tools that will automate the selection and management of the materialized data. In this paper we present DynaMat, a system that dynamically materializes information at multiple levels of granularity in order to match the demand (workload) but also takes into account the maintenance restrictions for the warehouse, such as down time to update the views and space availability. DynaMat unifies the view selection and the view maintenance problems under a single framework using a novel “goodness” measure for the materialized views. DynaMat constantly monitors incoming queries and materializes the best set of views subject to the space constraints. During updates, DynaMat reconciles the current materialized view selection and refreshes the most beneficial subset of it within a given maintenance window. We compare DynaMat against a system that is given all queries in advance and the pre-computed optimal static view selection. The comparison is made based on a new metric, the Detailed Cost Savings Ratio introduced for quantifying the benefits of view materialization against incoming queries. These experiments show that DynaMat's dynamic view selection outperforms the optimal static view selection and thus, any sub-optimal static algorithm that has appeared in the literature.
Storing semistructured data with STORED
Authors: Deutsch Alin , Fernandez Mary , Suciu Dan
Published: November 2005

Systems for managing and querying semistructured-data sources often store data in proprietary object repositories or in a tagged-text format. We describe a technique that can use relational database management systems to store and manage semistructured data. Our technique relies on a mapping between the semistructured data model and the relational data model, expressed in a query language called STORED. When a semistructured data instance is given, a STORED mapping can be generated automatically using data-mining techniques. We are interested in applying STORED to XML data, which is an instance of semistructured data. We show how a document-type-descriptor (DTD), when present, can be exploited to further improve performance.
Component-based e-commerce
Authors: Bichler Martin , Segev Arie , Zhao J. Leon
Published: November 2005

Component-based e-commerce technology
is a recent trend towards resolving the e-commerce challenge at both system and application levels. Instead of delivering a system as a prepacked monolith system containing any conceivable feature, component-based systems consist of a lightweight kernel to which new features can be added in the form of components. In order to identify the central problems in component-based e-commerce and ways to deal with them, we investigate prototypes, technologies, and frameworks that will transcend the current state of the practice in Internet commerce. In this paper, we first discuss the current practices and trends in component-based electronic commerce based on the International Workshop on Component-based Electronic Commerce. Then, we investigate a number of research issues and future directions in component-based development for electronic commerce.
Building database-driven electronic catalogs
Authors: Danish Sherif
Published: November 2005

This paper describes issues and solutions related to the creation of a product information database in the enterprise, and using this database as a foundation for deploying an electronic catalog. Today, product information is typically managed in document composition systems and communicated on paper. In the new wired world, these processes are undertaking fundamental changes to cope with the time to market pressure and the need for accurate, complete, and structured presentation of product information. Electronic catalogs are the answer.
XML and electronic commerce
Authors: Meltzer Bart , Glushko Robert
Published: November 2005

There has been a lot of talk about how the Internet is going to change the world economy. Companies will come together in a “plug and play” fashion to form trading partner networks. Virtual companies will be established and new business models can be created based on access to information and agents that can carry it around the world using computer networks.
A workflow-based electronic marketplace on the Web
Authors: Dogac Asuman , Durusoy Ilker , Arpinar Sena , Tatbul Nesime , Koksal Pinar , Cingil Ibrahim , Dimililer Nazife
Published: November 2005

In this paper, we describe an architecture for an open marketplace exploiting the workflow technology and the currently emerging data exchange and metadata representation standards on the Web.

In this market architecture electronic commerce is realized through the adaptable workflow templates provided by the marketplace to its users. Having workflow templates for electronic commerce processes results in a component-based architecture where components can be agents (both buying and selling) as well as existing applications invoked by the workflows. Other advantages provided by the workflow technology are forward recovery, detailed logging of the processes through workflow history manager and being able to specify data and control flow among the workflow components.

In the architecture proposed, the resources expose their metadata using Resource Description Framework (RDF) to be accessed by the resource discovery agents and their content through Extensible Markup Language (XML) to be accessed by the selling agents by using Document Object Model (DOM). The common set of Document Type Definitions (DTDs) are used to eliminate the need for an ontology.

The marketplace contains an Intelligent Directory Service (IDS) which makes it possible for agents to find out about each other through a match making mechanism. References to the related Document Type Definitions (DTDs) are stored in IDS. The IDS also contains the template workflows for buying and selling processes.
ADEPT
Authors: Jennings N. R. , Norman T. J. , Faratin P.
Published: November 2005

Successful companies organise and run their business activities in an efficient manner. Core activities are completed on time and within specified resource constraints. However to stay competitive in today's markets, companies need to continually improve their efficiency — business activities need to be completed more quickly, to higher quality and at lower cost. To this end, there is an increasing awareness of the benefits and potential competitive advantage that well designed business process management systems can provide. In this paper we argue the case for an agent-based approach: showing how agent technology can improve efficiency by ensuring that business activities are better scheduled, executed, monitored, and coordinated.
A componentized architecture for dynamic electronic markets
Authors: Reich Benny , Ben-Shaul Israel
Published: November 2005

The emergence and growing popularity of Internet-based electronic market-places, in their various forms, has raised the challenge to explore genericity in market design. In this paper we present a domain-specific software architecture that delineates the abstract components of a generic market and specifies control and data-flow constraints between them, and a framework that allows convenient pluggability of components that implement specific market policies. The framework was realized in the GEM system. GEM provides infrastructure services that allow market designers to focus solely on market-issues. In addition, it allows dynamic (re)configuration of components. This functionality can be used to change market-policies as the environment or market trends change, adding another level of flexibility to market designers and administrators.
Discovering Internet marketing intelligence through online analytical web usage mining
Authors: Büchner Alex G. , Mulvenna Maurice D.
Published: November 2005

This article describes a novel way of combining data mining techniques on Internet data in order to discover actionable marketing intelligence in electronic commerce scenarios. The data that is considered not only covers various types of server and web meta information, but also marketing data and knowledge. Furthermore, heterogeneity resolution thereof and Internet- and electronic commerce-specific pre-processing activities are embedded. A generic web log data hypercube is formally defined and schematic designs for analytical and predictive activities are given. From these materialised views, various online analytical web usage data mining techniques are shown, which include marketing expertise as domain knowledge and are specifically designed for electronic commerce purposes.
Semantic integration of environmental models for application to global information systems and decision-making
Authors: Mackay D. Scott
Published: November 2005

Global information systems have the potential of providing decision makers with timely spatial information about earth systems. This information will come from diverse sources, including field monitoring, remotely sensed imagery, and environmental models. Of the three the latter has the greatest potential of providing regional and global scale information on the behavior of environmental systems, which may be vital for setting multi-governmental policy and for making decisions that are critical to quality of life. However, environmental models have limited prootocol for quality control and standardization. They tend to have weak or poorly defined semantics and so their output is often difficult to interpret outside a very limited range of applications for which they are designed. This paper considers this issue with respect to spatially distributed environmental models. A method of measuring the semantic proximity between components of large, integrated models is presented, along with an example illustrating its application. It is concluded that many of the issues associated with weak model semantics can be resolved with the addition of self-evaluating logic and context-based tools that present the semantic weaknesses to the end-user.
Unpacking the semantics of source and usage to perform semantic reconciliation in large-scale information systems
Authors: Smith Ken , Obrst Leo
Published: November 2005

Semantic interoperability is a growing challenge in the United States Department of Defense (DoD). In this paper, we describe the basis of an infrastructure for the reconciliation of relevant, but semantically heterogeneous attribute values. Three types of information are described which can be used to infer the context of attributes, making explicit hidden semantic conflicts and making it possible to adjust values appropriately. Through an extended example, we show how an automated integration agent can derive the transformations necessary to perform four tasks in a simple semantic reconciliation.
Semantic video indexing
Authors: Hampapur Arun
Published: November 2005

Providing concept level access to video data requires, video management systems tailored to the domain of the data. Effective indexing and retrieval for high-level access mandates the use of domain knowledge. This paper proposes an approach based on the use of knowledge models to building domain specific video information systems. The key issues in such systems are identified and discussed.
Contextualizing the information space in federated digital libraries
Authors: Papazoglou M. P. , Hoppenbrouwers J.
Published: November 2005

Rapid growth in the volume of documents, their diversity, and terminological variations render federated digital libraries increasingly difficult to manage. Suitable abstraction mechanisms are required to construct meaningful and scalable document clusters, forming a cross-digital library information space for browsing and semantic searching. This paper addresses the above issues, proposes a distributed semantic framework that achieves a logical partitioning of the information space according to topic areas, and provides facilities to contextualize and landscape the available document sets in subject-specific categories.
Video anywhere
Authors: Sheth Amit , Bertram Clemens , Shah Kshitij
Published: November 2005

Visual information, especially videos, plays an increasing role in our society for both work and entertainment as more sources become available to the user. Set-top boxes are poised to give home users access to videos that come not only from TV channels and personal recordings, but also from the Internet in the form of downloaded and streaming videos of various types. Current approaches such as Electronic Program Guides and video search engines search for video assets of one type or from one source. The capability to conveniently search through many types of video assets from a large number of video sources with easy-to-use user profiles cannot be found anywhere yet.
VideoAnywhere
has developed such a capability in the form of an extensible architecture as well as a specific implementation using the latest in Internet programming (Java, agents, XML, etc.) and applicable standards. It automatically extracts and manages an extensible set of metadata of major types of videos that can be queried using either attribute-based or keyword-based search. It also provides user profiling that can be combined with the query processing for filtering. A user-friendly interface provides management of all system functions and capabilities.
VideoAnywhere
can also be used as a video search engine for the Web, and a servlet-based version has also been implemented.
SQL
Authors: Eisenberg Andrew , Melton Jim
Published: November 2005

For several years now, you've been hearing and reading about an emerging standard that everybody has been calling SQL3. Intended as a major enhancement of the current second generation SQL standard, commonly called SQL-92 because of the year it was published, SQL3 was originally planned to be issued in about 1996…but things didn't go as planned.

As you may be aware, SQL3 has been characterized as “object-oriented SQL” and is the foundation for several object-relational database management systems (including Oracle's ORACLE8, Informix' Universal Server, IBM's DB2 Universal Database, and Cloudscape's Cloudscape, among others). This is widely viewed as a “good thing”, but it has had a downside, too: it took nearly 7 years to develop, instead of the planned 3 or 4.

As we shall show, SQL:1999 is much more than merely SQL-92 plus object technology. It involves additional features that we consider to fall into SQL's relational heritage, as well as a total restructuring of the standards documents themselves with an eye towards more effective standards progression in the future.
Cost estimation of user-defined methods in object-relational database systems
Authors: Boulos Jihad , Ono Kinji
Published: November 2005

In this paper we present a novel technique for cost estimation of user-defined methods in advanced database systems. This technique is based on multi-dimensional histograms. We explain how the system collects statistics on the method that a database user defines and adds to the system. From these statistics a multi-dimensional histogram is built. Afterwards, this histrogram can be used for estimating the cost of the target method whenever this method is referenced in a query. This cost estimation is needed by the optimizer of the database system since this cost estimation needs to know the cost of a method in order to place it at its optimal position in the Query Execution Plan (QEP). We explain here how our technique works and we provide an example to better verify its functionality.
First-class views
Authors: Rosenthal Arnon , Sciore Edward
Published: November 2005

Large database systems (e.g., federations, warehouses) are
multi-layer
— i.e., a combination of
base
databases and (virtual or physical)
view
databases
1
. Smaller systems use views for layers that hide detailed physical and conceptual structures. We argue that most databases would be more effective if they were more
user-centered
— i.e., if they allowed users, administrators, and application developers to work mostly within their native view. To do so, we need
first class views
— views that support most of the metadata and operations available on source tables.

First class views could also make multi-tier object architectures (based on objects in multiple tiers of servers) easier to build and maintain. The views modularize code for data services (e.g., query, security) and for coordinating changes with neighboring tiers. When data in each tier is derived declaratively, one can generate some of these methods semi-automatically.

Much of the functionality required to support first class views can be generated semi-automatically, if the derivations between layers are declarative (e.g., SQL, rather than Java). We present a framework where
propagation rules
can be defined, allowing the flexible and incremental specification of view semantics, even by non-programmers. Finally, we describe research areas opened up by this approach.
A distributed scientific data archive using the Web, XML and SQL/MED
Authors: Papiani Mark , Wason Jasmin L. , Dunlop Alistair N. , Nicole Denis A.
Published: November 2005

We have developed a web-based architecture and user interface for fast storage, searching and retrieval of large, distributed, files resulting from scientific simulations. We demonstrate that the new DATALINK type defined in the draft SQL Management of External Data Standard can help to overcome problems associated with limited bandwidth when trying to archive large files using the web. We also show that separating the user interface specification from the user interface processing can provide a number of advantages. We provide a tool to generate automatically a default user interface specification, in the form of an XML document, for a given database. This facilitates deployment of our system by users with little web or database development experience. The XML document can be customised to change the appearance of the interface.
An overview and classification of mediated query systems
Authors: Domenig Ruxandra , Dittrich Klaus R.
Published: November 2005

Multimedia technology, global information infrastructures and other developments allow users to access more and more information sources of various types. However, the “technical” availability alone (by means of networks, WWW, mail systems, databases, etc.) is not sufficient for making meaningful and advanced use of all information available on-line. Therefore, the problem of effectively and efficiently accessing and querying heterogeneous and distributed data sources is an important research direction. This paper aims at classifying existing approaches which can be used to query heterogeneous data sources. We consider one of the approaches — the
mediated query approach
— in more detail and provide a classification framework for it as well.
Data mining on an OLTP system (nearly) for free
Authors: Riedel Erik , Faloutsos Christos , Ganger Gregory R. , Nagle David F.
Published: November 2005

This paper proposes a scheme for scheduling disk requests that takes advantage of the ability of high-level functions to operate directly at individual disk drives. We show that such a scheme makes it possible to support a Data Mining workload on an OLTP system almost for free: there is only a small impact on the throughput and response time of the existing workload. Specifically, we show that an OLTP system has the disk resources to consistently provide one third of its sequential bandwidth to a background Data Mining task with close to zero impact on OLTP throughput and response time at high transaction loads. At low transaction loads, we show much lower impact than observed in previous work. This means that a production OLTP system can be used for Data Mining tasks without the expense of a second dedicated system. Our scheme takes advantage of close interaction with the on-disk scheduler by reading blocks for the Data Mining workload as the disk head “passes over” them while satisfying demand blocks from the OLTP request stream. We show that this scheme provides a consistent level of throughput for the background workload even at very high foreground loads. Such a scheme is of most benefit in combination with an Active Disk environment that allows the background Data Mining application to also take advantage of the processing power and memory available directly on the disk drives.
Turbo-charging vertical mining of large databases
Authors: Shenoy Pradeep , Haritsa Jayant R. , Sudarshan S. , Bhalotia Gaurav , Bawa Mayank , Shah Devavrat
Published: November 2005

In a vertical representation of a market-basket database, each
item
is associated with a column of values representing the transactions in which it is present. The association-rule mining algorithms that have been recently proposed for this representation show performance improvements over their classical horizontal counterparts, but are either efficient only for certain database sizes, or assume particular characteristics of the database contents, or are applicable only to specific kinds of database schemas. We present here a new vertical mining algorithm called VIPER, which is general-purpose, making no special requirements of the underlying database. VIPER stores data in compressed bit-vectors called “snakes” and integrates a number of novel optimizations for efficient snake generation, intersection, counting and storage. We analyze the performance of VIPER for a range of synthetic database workloads. Our experimental results indicate significant performance gains, especially for large databases, over previously proposed vertical and horizontal mining algorithms. In fact, there are even workload regions where VIPER outperforms an optimal, but practically infeasible, horizontal mining algorithm.
Synchronizing a database to improve freshness
Authors: Cho Junghoo , Garcia-Molina Hector
Published: November 2005

In this paper we study how to refresh a local copy of an autonomous data source to maintain the copy up-to-date. As the size of the data grows, it becomes more difficult to maintain the copy \ fresh, “making it crucial to synchronize the copy effectively. We define two freshness metrics, change models of the underlying data, and synchronization policies. We analytically study how effective the various policies are. We also experimentally verify our analysis, based on data collected from 270 web sites for more than 4 months, and we show that our new policy improves the \ freshness” very significantly compared to current policies in use.
How to roll a join
Authors: Salem Kenneth , Beyer Kevin , Lindsay Bruce , Cochrane Roberta
Published: November 2005

Incremental refresh of a materialized join view is often less expensive than a full, non-incremental refresh. However, it is still a potentially costly atomic operation. This paper presents an algorithm that performs incremental view maintenance as a series of small, asynchronous steps. The size of each step can be controlled to limit contention between the refresh process and concurrent operations that access the materialized view or the underlying relations. The algorithm supports point-in-time refresh, which allows a materialized view to be refreshed to any time between the last refresh and the present.
LH*RS
Authors: Litwin Witold , Schwarz Thomas
Published: November 2005

LH*
RS
is a new high-availability Scalable Distributed Data Structure (SDDS). The data storage scheme and the search performance of LH*
RS
are basically these of LH*. LH*
RS
manages in addition the parity information to tolerate the unavailability of k ⪈ 1 server sites. The value of k scales with the file, to prevent the reliability decline. The parity calculus uses the Reed -Solomon Codes. The storage and access performance overheads to provide the high-availability are about the smallest possible. The scheme should prove attractive to data-intensive applications.