icde_1996_elementary.txt

利用lwp：：get写的

<proceedings><paper><title>Program Chair's Message</title><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract></abstract></paper><paper><title>In Memoriam-Gennady Antoshenkov</title><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract></abstract></paper><paper><title>External Referees</title><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract></abstract></paper><paper><title>Are We Moving Toward an Information Superhighway or a tower of Babel? The Challenge of Large-Scale Semantic Heterogeneity</title><author><AuthorName>Stuart E. Madnick</AuthorName><institute><InstituteName>MI</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>The popularity and growth of the &amp;quot;Information Super Highway&amp;quot; have dramatically increased the number of information sources available for use. Unfortunately, there are significant challenges to be overcome. One particular problem is context interchange, whereby each source of information and potential receiver of that information may operate with a different context, leading to large-scale semantic heterogeneity. A context is the collection of implicit assumptions about the context definition (i.e., meaning) and context characteristics (i.e., quality) of the information. This paper describes various forms of context challenges and examples of potential context mediation services, such as data semantics acquisition, data quality attributes, and evolving semantics and quality, that can mitigate the problem.</abstract></paper><paper><title>Applying a Flexible OODBMS-IRS-Coupling to Structured Document Handling</title><author><AuthorName>Marc Volz</AuthorName><institute><InstituteName>GMD-IPSI, Darmstadt, German</InstituteName><country></country></institute></author><author><AuthorName>Karl Aberer</AuthorName><institute><InstituteName>GMD-IPSI, Darmstadt, German</InstituteName><country></country></institute></author><author><AuthorName>Klemens Boehm</AuthorName><institute><InstituteName>GMD-IPSI, Darmstadt, German</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>In document management systems it is desirable to provide content-based access to documents going beyond regular expression search in addition to access based on structural characteristics or associated attributes. We present a new approach for coupling OODBMSs (Object Oriented Database Management Systems) and IRSs (Information Retrieval Systems) that provides enhanced flexibility and functionality as compared to coupling approaches reported from the literature. Our approach allows to decide freely to which document collections, that are used as retrieval context, document objects belong, which text contents they provide for retrieval and how they derive their associated retrieval values, either directly from the retrieval machine or from the values of related objects. Especially, we show how in this approach different strategies can be applied to hierarchically structured documents, possibly avoiding redundancy and IRS or OODBMS peculiarities. Content-based and structural queries can be freely combined within the OODBMS query language.</abstract></paper><paper><title>A Log-Structured Organization for Tertiary Storage</title><author><AuthorName>D.A. Ford</AuthorName><institute><InstituteName>Department of Computer Science, IBM Almaden Research Center, San Jose, C</InstituteName><country></country></institute></author><author><AuthorName>J. Myllymaki</AuthorName><institute><InstituteName>Computer Sciences Department, University of Wisconsin-Madison, Madison, W</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>We present the design of a log-structured tertiary storage system (LTS). The advantage of this approach is that it allows the system to hide the details of juke-box robotics and media characteristics behind a uniform, random access, block-oriented interface. It also allows the system to avoid media mount operations for writes, giving write performance similar to that of secondary storage.</abstract></paper><paper><title>Secure Mediated Databases</title><author><AuthorName>K.S. Candan</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><author><AuthorName>S. Jajodia</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><author><AuthorName>V.S. Subrahmanian</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>With the evolution of the information superhighway, there is now an immense amount of information available in a wide variety of databases. Furthermore, users often have the ability to access legacy software packages developed by external sources. However, sometimes both the information provided by a data source, as well as one or more of the functions available through a software package may be sensitive-in such cases, organizations require that access by users be controlled. HERMES (HEterogeneous Reasoning and MEdiator System) is a platform that has been developed at the University of Maryland within which mediators may be designed and implemented. HERMES has already been used for a number of applications. In this paper, we provide a formal model of security in mediated systems. We then develop techniques that are sound and complete and respect security constraints of packages/databases participating in the mediated system. The security constraints described an this paper have been implemented, and we describe the existing implementation.</abstract></paper><paper><title>Authorization and Access Control in IRO-DB</title><author><AuthorName>W. Essmayr</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><author><AuthorName>F. Kastner</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><author><AuthorName>G. Pernul</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><author><AuthorName>S. Preishuber</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><author><AuthorName>and A M. Tjoa</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract></abstract></paper><paper><title>Query Folding</title><author><AuthorName>Xiaolei Qian</AuthorName><institute><InstituteName>Computer Science Laboratory, SRI Internationa</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>Query folding refers to the activity of determining if and how a query can be answered using a given set of resources, which might be materialized views, cached results of previous queries, or queries answerable by other databases. We investigate query folding in the context where queries and resources are conjunctive queries. We develop an exponential-time algorithm that finds all complete or partial foldings, and a polynomial-time algorithm for the subclass of acyclic conjunctive queries. Our results can be applied to query optimization in centralized databases, to query processing in distributed databases, and to query answering in federated databases.</abstract></paper><paper><title>A Toolkit for Constraint Management in Heterogeneous Information Systems*</title><author><AuthorName>S.S. Chawathe</AuthorName><institute><InstituteName>Department of Computer Science, Stanford University, Stanford, C</InstituteName><country></country></institute></author><author><AuthorName>H. Garcia-Molina</AuthorName><institute><InstituteName>Department of Computer Science, Stanford University, Stanford, C</InstituteName><country></country></institute></author><author><AuthorName>J. Widom</AuthorName><institute><InstituteName>Department of Computer Science, Stanford University, Stanford, C</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>We present a framework and a toolkit to monitor and enforce distributed integrity constraints in loosely coupled heterogeneous information systems. Our framework enables and formalizes weakened notions of consistency, which are essential in such environments. Our framework is used to describe (1) intelfaces provided by a database for the data items involved in inter-site constraints; (2) strategies for monitoring and enforcing such constraints, (3) guarantees regarding the level of consistency the system can provide. Our toolkit uses this framework to provide a set of configurable modules thatare used to monitorand en- force constraints spanning loosely coupled heterogeneous information systems.</abstract></paper><paper><title>Improving the Performance of Multi-Dimensional Access Structures Based on k-d-Trees</title><author><AuthorName>Andreas Henrich</AuthorName><institute><InstituteName>Universit鋞 Siegen, Siegen, German</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>In recent years, various k-d-tree based multi-dimensional access structures have been proposed. All these structures share an average bucket utilization of at most ln 2 (about 69.3 %). In this paper we present two algorithms which perform local redistributions of objects to improve the storage utilization of these access structures. We show that under fair conditions a good improvement algorithm can save up to 20 % of space and up to 15 % of query processing time. On the other hand we also show that a local redistribution scheme designed without care, can improve the storage utilization and at the same time worsen the performance of range queries drastically. Furthermore we show the dependencies between split strategies and local redistribution schemes and the general limitations which can be derived from these dependencies.</abstract></paper><paper><title>A HiTi Graph Model of Topographical Road Maps in Navigation Systems</title><author><AuthorName>Sungwon Jung</AuthorName><institute><InstituteName>Department of Computer Science, Michigan State Universit</InstituteName><country></country></institute></author><author><AuthorName>Sakti Pramanik</AuthorName><institute><InstituteName>Department of Computer Science, Michigan State Universit</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>In navigation systems, a primary task is to compute the minimum cost route from the current location to the destination. One of the major problems for navigation systems is that a significant amount of computation time is required to find a minimum cost path when the topographical road map is large. Since navigation systems are real time systems, it is critical that the path be computed while satisfying a time constraint. In this paper, we propose a new graph model named HiTi (Hierarchical mulTi graph model), for efficiently computing an optimal minimum cost path. Based on HiTi graph model, we propose a new single pair minimum cost path algorithm. We empirically show that our proposed algorithm performs far better than the traditional A* algorithm. Further, we empirically analyze our algorithm by varying both edge cost distribution and hierarchical level number of HiTi graphs.</abstract></paper><paper><title>Representing Retroactive and Proactive Versions in Bi-Temporal DataBases (2TDB)</title><author><AuthorName>Jongho Won</AuthorName><institute><InstituteName>Department of Computer Science and Engineering, The University of Texas at Arlingto</InstituteName><country></country></institute></author><author><AuthorName>Ramez Elmasri</AuthorName><institute><InstituteName>Department of Computer Science and Engineering, The University of Texas at Arlingto</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>Bi-Temporal databases allow users to record retroactive (past) and proactive (future planned) versions of an entity, and to retrieve the appropriate versiosns for bi-temporal queries that involve both valid-time and transaction-time. Currently used timestamp representations are mainly for either valid-time or transaction-time databases. In this paper, we first categorize the types of problems that can occur in existing models. These are (1) ambiguity, (2) priority specification, and (3) lost information. We then propose a 2TDB model that allows both retroactive and proactive versions, overcomes the identified problems, and permits the correction of recorded facts.</abstract></paper><paper><title>Mining Knowledge Rules from Databases: A Rough Set Approach</title><author><AuthorName>Xiaohua Hu</AuthorName><institute><InstituteName>Bell-Northern Research Ltd</InstituteName><country></country></institute></author><author><AuthorName>Nick Cercone</AuthorName><institute><InstituteName>Univ. of Regin</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>In this paper, the principle and experimental results of an attribute-oriented rough set approach for knowledge discovery in databases are described. Our method integrates the database operation, rough set theory and machine learning techniques. In our method, we consider the learning procedure consists of two phases: data generalization and data reduction. In data generalization phase, the attribute-oriented induction is performed attribute by attribute using attribute removal and concept ascension, some undesirable attributes to the discovery task are removed and the primitive data is generalized to the desirable level, thus a set of tuples may be generalized to the same generalized tuple, this procedure substantially reduces the computational complexity of the database learning process. Subsequently, in data reduction phase, the rough set method is applied to the generalized relation to find a minimal attribute set relevant to the learning task. The generalized relation is reduced further by removing those attributes which are irrelevant and/or unimportant to the learning task. Finally the tuples in the reduced relation are transformed into different knowledge rules based on different knowledge discovery algorithms. Based upon these principles, a prototype knowledge discovery system DBROUGH has been constructed. In DBROUGH, a variety of knowledge discovery algorithms are incorporated and different kinds of knowledge rules, such as characteristic rules, classification rules, decisions rules, maximal generalized rules can be discovered efficiently and effectively from large databases.</abstract></paper><paper><title>Maintenance of Discovered Association Rules in Large Databases: An Incremental Updating Techniques</title><author><AuthorName>David W. Cheung</AuthorName><institute><InstituteName>The University of Hong Kon</InstituteName><country></country></institute></author><author><AuthorName>C. Y. Wong</AuthorName><institute><InstituteName>The University of Hong Kon</InstituteName><country></country></institute></author><author><AuthorName>Jiawei Han</AuthorName><institute><InstituteName>Simon Fraser Universit</InstituteName><country></country></institute></author><author><AuthorName>Vincent T. Ng</AuthorName><institute><InstituteName>Hong Kong Polytechnic Universit</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>An incremental updating technique is developed for maintenance of the association rules discovered by database mining. There have been many studies on efficient discovery of association rules in large databases. However, it is nontrivial to maintain such discovered rules in large databases because a database may allow frequent or occasional updates and such updates may not only invalidate some existing strong association rules but also turn some weak rules into strong ones. In this study, an incremental updating technique is proposed for efficient maintenance of discovered association rules when new transaction data are added to a transaction database.</abstract></paper><paper><title>Knowledge discovery from telecommunication network alarm databases</title><author><AuthorName>K. Hatonen</AuthorName><institute><InstituteName>Dept. of Comput. Sci., Helsinki Univ., Finlan</InstituteName><country></country></institute></author><author><AuthorName>M. Klemettinen</AuthorName><institute><InstituteName>Dept. of Comput. Sci., Helsinki Univ., Finlan</InstituteName><country></country></institute></author><author><AuthorName>H. Mannila</AuthorName><institute><InstituteName>Dept. of Comput. Sci., Helsinki Univ., Finlan</InstituteName><country></country></institute></author><author><AuthorName>P. Ronkainen</AuthorName><institute><InstituteName>Dept. of Comput. Sci., Helsinki Univ., Finlan</InstituteName><country></country></institute></author><author><AuthorName>H. Toivonen</AuthorName><institute><InstituteName>Dept. of Comput. Sci., Helsinki Univ., Finlan</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>A telecommunication network produces daily large amounts of alarm data. The data contains hidden valuable knowledge about the behavior of the network. This knowledge can be used in filtering redundant alarms, locating problems in, the network, and possibly in predicting severe faults. We describe the TASA (Telecommunication Network Alarm Sequence Analyzer) system for discovering and browsing knowledge from large alarm databases. The system is built on the basis of viewing knowledge discovery as an interactive and iterative process, containing data collection, pattern discovery, rule postprocessing, etc. The system uses a novel framework for locating frequently occurring episodes from sequential data. The TASA system offers a variety of selection and ordering criteria for episodes, and supports iterative retrieval from the discovered knowledge. This means that a large part of the iterative nature of the KDD process can be replaced by iteration in the rule postprocessing stage. The user interface is based on dynamically generated HTML. The system is in experimental use, and the results are encouraging: some of the discovered knowledge is being integrated into the alarm handling software of telecommunication operators.</abstract></paper><paper><title>An Executable Graphical Representation of Mediatory Information Systems</title><author><AuthorName>Jacques Calmet</AuthorName><institute><InstituteName>Institute for Algorithms and Cognitive Systems, University of Karlsruh</InstituteName><country></country></institute></author><author><AuthorName>Dirk Debertin</AuthorName><institute><InstituteName>Institute for Algorithms and Cognitive Systems, University of Karlsruh</InstituteName><country></country></institute></author><author><AuthorName>Sebastian Jekutsch</AuthorName><institute><InstituteName>Institute for Algorithms and Cognitive Systems, University of Karlsruh</InstituteName><country></country></institute></author><author><AuthorName>Joachim Schu</AuthorName><institute><InstituteName>Institute for Algorithms and Cognitive Systems, University of Karlsruh</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>In this paper we present an approach towards a unified modeling and query-processing tool for mediatory information systems. Based upon Coloured Petri nets we are able to model the integration of parametric data (external, uncertain and temporal informations) and to visualize the dataflow in mediatory information systems.</abstract></paper><paper><title>MedMaker: A Mediation System Based System Based on Declarative Specifications</title><author><AuthorName>Y. Papakonstantinou</AuthorName><institute><InstituteName>Computer Science Department, Stanford University, Stanford, CA, US</InstituteName><country></country></institute></author><author><AuthorName>H. Garcia-Molina</AuthorName><institute><InstituteName>Computer Science Department, Stanford University, Stanford, CA, US</InstituteName><country></country></institute></author><author><AuthorName>J. Ullman</AuthorName><institute><InstituteName>Computer Science Department, Stanford University, Stanford, CA, US</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>Mediators are used for integration of heterogeneous information sources. We present a system for declaratively specifying mediators. It is targeted for integration of sources with unstructured or semi-structured data and/or sources with changing schemas. We illustrate the main features of the Mediator Specification Language (MSL), show how they facilitate integration, and describe the implementation of the system that interprets the MSL specifications.</abstract></paper><paper><title>A Directory Service for a Federation of CIM Databases with Migrating Objects</title><author><AuthorName>Ajit K. Patankar</AuthorName><institute><InstituteName>Lawrence Berkeley National Laborator</InstituteName><country></country></institute></author><author><AuthorName>Arie Segev</AuthorName><institute><InstituteName>Lawrence Berkeley National Laborator</InstituteName><country></country></institute></author><author><AuthorName>J. George Shanthikumar</AuthorName><institute><InstituteName>Lawrence Berkeley National Laborator</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>We propose a novel directory scheme for a large federation of databases where object migration is in response to manufacturing events. In our directory scheme, objects report their location to a directory server instead of the traditional method of the directory servers polling sites in the network. The directory is distributed among multiple servers to avoid bottleneck during query processing. A distributed Linear Hashing algorithm is proposed for efficiently determining an appropriate server for an object. Finally, a stochastic dynamic programming model is proposed for minimizing the number of database transactions.</abstract></paper><paper><title>Data Cube: A Relational Aggregation Operator Generalizing Group-By, Cross-Tab, and Sub-Totals</title><author><AuthorName>Jim Gray</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><author><AuthorName>Adam Bosworth</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><author><AuthorName>Andrew Layman</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><author><AuthorName>Hamid Pirahesh</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract></abstract></paper><paper><title>Transaction Coordination for the New Millennium: SQL Server Meets OLE Transactions</title><author><AuthorName>D.G. Campbell</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract></abstract></paper><paper><title>Search and ranking algorithms for locating resources on the World Wide Web</title><author><AuthorName>B. Yuwono</AuthorName><institute><InstituteName>Dept. of Comput. &amp; Inf. Sci., Ohio State Univ., Columbus, OH, US</InstituteName><country></country></institute></author><author><AuthorName>D.L. Lee</AuthorName><institute><InstituteName>Dept. of Comput. &amp; Inf. Sci., Ohio State Univ., Columbus, OH, US</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>Applying information retrieval techniques to the World Wide Web (WWW) environment is a challenge, mostly because of its hypertext/hypermedia nature and the richness of the meta-information it provides. We present four keyword-based search and ranking algorithms for locating relevant WWW pages with respect to user queries. The first algorithm, Boolean Spreading Activation, extends the notion of word occurrence in the Boolean retrieval model by propagating the occurrence of a query word in a page to other pages linked to it. The second algorithm, Most-cited, uses the number of citing hyperlinks between potentially relevant WWW pages to increase the relevance scores of the referenced pages over the referencing pages. The third algorithm, TFxIDF vector space model, is based on word distribution statistics. The last algorithm, Vector Spreading Activation, combines TFxIDF with the spreading activation model. We conducted an experiment to evaluate the retrieval effectiveness of these algorithms. From the results of the experiment, we draw conclusions regarding the nature of the WWW environment with respect to document ranking strategies.</abstract></paper><paper><title>The Gold Text Indexing Engine</title><author><AuthorName>D. Barbara</AuthorName><institute><InstituteName>MITL 2 Research Way Princeton, NJ, US</InstituteName><country></country></institute></author><author><AuthorName>S. Mehrotra</AuthorName><institute><InstituteName>MITL 2 Research Way Princeton, NJ, US</InstituteName><country></country></institute></author><author><AuthorName>P. Vallabhaneni</AuthorName><institute><InstituteName>MITL 2 Research Way Princeton, NJ, US</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>The proliferation of electronic communication including computer mail, faxes, voice mail, and net news has led to a variety of disjoint applications and usage paradigms that forces users to deal with multiple different user interfaces and access related information arriving over the different communication media separately. To enable users to cope with the overload of information arriving over heterogeneous communication media, we have developed the Gold document handling system that allows users to access all of these forms of communication at once, or to intermix them. The Gold system provides users with an integrated way to send and recieve messages using different media, efficiently store the messages, retrieve the messages based on their contents, and to access a variety of other sources of useful information. At the center of the Gold document handling system is the Gold Text Indexing Engine (GTIE) that provides a full text index over the documents. The paper describes our implementation of GTIE and the concurrency control protocols to ensure consistency of the index in the presence of concurrent operations.</abstract></paper><paper><title>Speculative Data Dissemination and Service to Reduce Server Load, Network Traffic and Service Time in Distributed Information Systems</title><author><AuthorName>Azer Bestavros</AuthorName><institute><InstituteName>Computer Science Department, Boston University, M</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>We present two server-initiated protocols to improve the performance of distributed information systems WWW. Our first protocol is a hierarchical data dissemination mechanism that allows information to propagate from its producers to servers that are closer to its consumers. This dissemination reduces network traffic and balances load amongst servers by exploiting geographic and temporal locality of reference properties exhibited in client access patterns. Our second protocol relies on speculative service, whereby a request for a document is serviced by sending, in addition to the document requested, a number of other documents that the server speculates will be requested in the near future. This speculation reduces service time by exploiting the spatial locality of reference property. We present results of trace-driven simulations that quantify the attainable performance gains for both protocols.</abstract></paper><paper><title>DB2 LOBs: The Teenage Years</title><author><AuthorName>T. J. Lehman</AuthorName><institute><InstituteName>IBM Almaden Research Cente</InstituteName><country></country></institute></author><author><AuthorName>P. J. Gainer</AuthorName><institute><InstituteName>IBM Almaden Research Cente</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>Previous versions of DB2 Common Server had large objects (LOBs) that were neither large nor functional. Their size was limited to 32,700 bytes and, until recently when support for SUBSTR and CONCAT was added, there was no function available on these objects at all. DB2 LOBs were infants. However, with the latest release of DB2 Common Server, Version 2.1, LOBs have matured considerably, supporting significantly larger sizes and many new language features. To give the reader a feeling for the extent of this new language support, we compare our new SQL LOB language features with that of three other major Relational database competitors: Sybase, Informix and Oracle. Users will find the new DB2 LOBS easy to load and store, easy to search, and easy to integrate into the DB2 user-defined functions (UDFs) and user-defined types (UDTs). In addition, when used in serial mode, the performance of LOB I/O rivals that of file systems and, when used in parallel mode, is a clear winner. DB2 LOBs have now entered the teenage years.</abstract></paper><paper><title>Database Extensions for Complex Domains</title><author><AuthorName>S. DeFazio</AuthorName><institute><InstituteName>Oracle Corporation, New England Development Center, Nashua, New Hampshir</InstituteName><country></country></institute></author><author><AuthorName>J. Srinivasan</AuthorName><institute><InstituteName>Oracle Corporation, New England Development Center, Nashua, New Hampshir</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>Future versions of the Oracle Server will provide an open and extensible framework for supporting complex data domains including, but not limited to, text, image, spatial, video, and OLAP. This framework encompasses features for defining, storing, updating, indexing, and retrieving complex forms of data with full transaction semantics. The underpinning for these features is an extended Oracle Server that is an object-relational database management system (ORDBMS).</abstract></paper><paper><title>OLE DB: A Component DBMS Architecture</title><author><AuthorName>J.A. Blakeley</AuthorName><institute><InstituteName>Microsoft Corporation, Redmond, WA</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>The article describes an effort at Microsoft whose primary goal is to enable applications to have uniform access to data stored in diverse DBMS and non DBMS information containers. Applications continue to take advantage of the benefits of database technology such as declarative queries, transactional access, and security without having to transfer data from its place of origin to a DBMS. Our approach consists of defining an open, extensible collection of interfaces that factor and encapsulate orthogonal, independently reusable portions of DBMS functionality. These interfaces define the boundaries of DBMS components arch as record containers, and query processors that enable uniform, transactional access to data among such components. The proposed interfaces extend Microsoft's OLE Component Object Model (COM) with database functionality, hence these interfaces are collectively referred to as OLE DB. The OLE DB functional areas include data access and updates (rowsets), query processing, catalog information, notifications, transactions, security, and distribution. The article presents an overview of the OLE DB approach and its areas of componentization.</abstract></paper><paper><title>Tioga-2: A Direct Manipulation Database Visualization Environment</title><author><AuthorName>Alexander Aiken</AuthorName><institute><InstituteName>Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, C</InstituteName><country></country></institute></author><author><AuthorName>Jolly Chen</AuthorName><institute><InstituteName>Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, C</InstituteName><country></country></institute></author><author><AuthorName>Michael Stonebraker</AuthorName><institute><InstituteName>Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, C</InstituteName><country></country></institute></author><author><AuthorName>Allison Woodruff</AuthorName><institute><InstituteName>Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, C</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>This paper reports on user experience with Tioga, a DBMS-centric visualization tool developed at Berkeley. Based on this experience, we have designed Tioga-2 as a direct manipulation system that is more powerful and much easier to program. A detailed design of the revised system is presented, together with an extensive example of its application.</abstract></paper><paper><title>Towards the Reverse Engineering of Denormalized Relational Databases</title><author><AuthorName>Jean-Marc Petit</AuthorName><institute><InstituteName>Laboratoire d'Ing閚ierie des Syst鑝es d'Information, INSA Lyon, Villeurbanne cede</InstituteName><country></country></institute></author><author><AuthorName>Farouk Toumani</AuthorName><institute><InstituteName>Laboratoire d'Ing閚ierie des Syst鑝es d'Information, INSA Lyon, Villeurbanne cede</InstituteName><country></country></institute></author><author><AuthorName>Jean-Francois Boulicaut</AuthorName><institute><InstituteName>Laboratoire d'Ing閚ierie des Syst鑝es d'Information, INSA Lyon, Villeurbanne cede</InstituteName><country></country></institute></author><author><AuthorName>Jacques Kouloumdjian</AuthorName><institute><InstituteName>Laboratoire d'Ing閚ierie des Syst鑝es d'Information, INSA Lyon, Villeurbanne cede</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>This paper describes a method to cope with denormalized relational schemas in a database reverse engineering process. We propose two main steps to improve the understanding of data semantics. Firstly we extract inclusion dependencies by analyzing the equi-join queries embedded in application programs and by querying the database extension. Secondly we show how to discover only functional dependencies which influence the way attributes should be restructured. The method is interactive since an expert user has to validate the presumptions on the elicited dependencies. Moreover, a restructuring phase leads to a relational schema in third normal form provided with key dependencies and referential integrity constraints. Finally, we sketch how an Entity-Relationship schema can be derived from such information.</abstract></paper><paper><title>A Graph-Theoretic Approach to Indexing in Object-Oriented Databases</title><author><AuthorName>Boris Shidlovsky</AuthorName><institute><InstituteName>DIIMA, University of Salerno, Ital</InstituteName><country></country></institute></author><author><AuthorName>Elisa Bertino</AuthorName><institute><InstituteName>DSI, University of Milan, Ital</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>A graph-theoretic approach to the path indexing problem is proposed. We represent the indexing relationships supported by indices allocated in the classes in the path in the form of a directed graph. All the previous approaches directly fit into the scheme and form a hierarchy of complexity with respect to the time required for selection of the optimal index configuration. Based on the general scheme, we develop a new approach to the path indexing problem exploiting the notion of visibility graph. We introduce a generalized nested-inherited index, give algorithms for retrieval and update operations and compare the behavior of the new structure with previous approaches.</abstract></paper><paper><title>A Uniform Indexing Scheme for Object-Oriented Databases</title><author><AuthorName>Ehud Gudes</AuthorName><institute><InstituteName>Department of Mathematics and Computer Science, Ben-Gurion University, Beer-Sheva, Israe</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>The performance of Object-oriented databases (OODB) is a critical factor hindering their current use. Several indexing schemes have been proposed in the literature for enhancing OODB performance and they are briefly reviewed here. In this paper a new and uniform indexing scheme is proposed. This scheme is based on a single B-tree and combines both the hierarchical and nested indexing schemes \cite{Bertino,Kim}. The uniformity of this scheme enables compact and optimized code dealing with a large range of queries on the one hand, and flexibility in adding and removing indexed paths on the other hand. The performance of the scheme is about the same as existing schemes for single-class, exact match or range queries, and much better for multi-class and other complex queries and update.</abstract></paper><paper><title>A Hybrid Object Clustering Strategy for Large Knowledge-Based Systems</title><author><AuthorName>Arun Ramanujapuram</AuthorName><institute><InstituteName>Department of Computer Science, University of Saskatchewan, Saskatoon, Canad</InstituteName><country></country></institute></author><author><AuthorName>Jim E. Greer</AuthorName><institute><InstituteName>Department of Computer Science, University of Saskatchewan, Saskatoon, Canad</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>Object bases underlying knowledge-based applications tend to be complex and require management. This research aims at improving the performance of object bases underlying a class of large knowledge-based systems that utilize object-oriented technology to engineer the knowledge base. In this paper, a hybrid clustering strategy that beneficially combines semantic clustering and iterative graph-paritioning techniques has been developed and evaluated for use in knowledge bases storing information in the form of object graphs. It is demonstrated via experimentation that such a technique is useful and feasible in realistic object bases. A semantic specification mechanism similar to placement trees has been developed for specifying the clustering. The workload and the nature of object graphs in knowledge bases differ significantly from those present in conventional object-oriented databases. Therefore, the evaluation has been performed by building a new benchmark called the Granularity Benchmark. A segmented storage scheme for the knowledge base using large object storage mechanisms of existing storage managers is also examined.</abstract></paper><paper><title>Parallel Processing of Spatial Joins Using R-trees</title><author><AuthorName>Thomas Brinkhoff</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><author><AuthorName>Hans-Peter Kriegel</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><author><AuthorName>Bernhard Seeger</AuthorName><institute><InstituteName></InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>Fachgebiet Informatik, Universit鋞 Marburg, Marburg, GermanyIn this paper, we show that spatial joins are very suitable to be processed on a parallel hardware platform. The parallel system is equipped with a so-called shared virtual memory which is well-suited for the design and implementation of parallel spatial join algorithms. We start with an algorithm that consists of three phases: task creation, task assignment and parallel task execution. In order to reduce CPU- and I/O-cost, the three phases are processed in a fashion that preserves spatial locality. Dynamic load balancing is achieved by splitting tasks into smaller ones and reassigning some of the smaller tasks to idle processors. In an experimental performance comparison, we identify the advantages and disadvantages of several variants of our algorithm. The most efficient one shows an almost optimal speed-up under the assumption that the number of disks is sufficiently large.</abstract></paper><paper><title>Parallel Pointer-Based Join Algorithms in Memory Mapped Environments</title><author><AuthorName>Peter A. Buhr</AuthorName><institute><InstituteName>Department of Computer Science, University of Waterloo, Ontario, Canad</InstituteName><country></country></institute></author><author><AuthorName>Anil K. Goel</AuthorName><institute><InstituteName>Department of Computer Science, University of Waterloo, Ontario, Canad</InstituteName><country></country></institute></author><author><AuthorName>Naomi Nishimura</AuthorName><institute><InstituteName>Department of Computer Science, University of Waterloo, Ontario, Canad</InstituteName><country></country></institute></author><author><AuthorName>Prabhakar Ragde</AuthorName><institute><InstituteName>Department of Computer Science, University of Waterloo, Ontario, Canad</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>Three pointer-based parallel join algorithms are presented and analyzed for environments in which secondary storage is made transparent to the programmer through memory mapping. Buhr, Goel, and Wai have shown that data structures such as B-Trees, R-Trees and graph data structures can be implemented as efficiently and effectively in this environment as in a traditional environment using explicit I/O. Here we show how higher-order algorithms, in particular parallel join algorithms, behave in a memory mapped environment. A quantitative analytical model has been developed to conduct performance analysis of the parallel join algorithms. The model has been validated by experiments.</abstract></paper><paper><title>Prefetching from a Broadcast Disk</title><author><AuthorName>Swarup Acharya</AuthorName><institute><InstituteName>Brown Universit</InstituteName><country></country></institute></author><author><AuthorName>Stanley Zdonik</AuthorName><institute><InstituteName>Brown Universit</InstituteName><country></country></institute></author><author><AuthorName>Michael Franklin</AuthorName><institute><InstituteName>University of Marylan</InstituteName><country></country></institute></author><year>1996</year><conference>International Conference on Data Engineering</conference><citation></citation><abstract>Broadcast Disks have been proposed as a means to efficiently deliver data to clients in ``asymmetric'' environments where the available bandwidth from the server to the clients greatly exceeds the bandwidth in the opposite direction. A previous study investigated the use of cost-based caching to improve performance when clients access the broadcast in a demand-driven manner [. achas 95 .]. Such demand-driven access however, does not fully exploit the dissemination-based nature of the broadcast, which is particularly conducive to client {\em prefetching}. With a Broadcast Disk, pages continually flow past the clients so that, in contrast to traditional environments, prefetching can be performed without placing additional load on shared resources. We argue for the use of a simple prefetch heuristic called \PT{} and show that \PT{} balances the cache residency time of a data item with its bandwidth allocation. Because of this tradeoff, \PT{} is very tolerant of variations in the broadcast program. We describe an implementable approximation for \PT{} and examine its sensitivity to access probability estimation errors. The results show that the technique is effective even when the probability estimation is substantially different from the actual values.</abstract></paper><paper><title>ActionWorkflow