The Collaboration Management lnfrastructure (CMI) has been developed at MCC to manage collaboration processes in both traditional and virtual enterprises, and to provide combined process and situation awareness. CMI technology development is driven by the requirements of many advanced applications provided by the companies that are members of the consortial CMI project. Such advanced applications include crisis mitigation, command and control, logistics, and service provisioning in virtual enterprises. These applications are not effectively supported by existing workflow and groupware technologies. To address the requirements imposed by these applications CMI provides a sophisticated Collaboration Management Model (CMM) and a corresponding component-oriented system that implements the CMM. CMM draws existing primitives from workflow and groupware models and introduces new primitives that address previously unsupported requirements of the CMI driver applications. In this paper, a crisis mitigation application is presented that involves several process templates which are extended dynamically as details about the crisis become known.

The unprecedented growth in the volume of online information has led to an information explosion which has made producing queries over this information difficult. In this paper, we examine an automated mechanism which allows users to access this information in a structured manner by analyzing unstructured text by domain-specific ontologies, annotating these documents using XML tags and using specific query processing techniques. Our approach is to use focused linguistic techniques over a limited context of an ontology for the identification and annotation of basic concepts and relationships in textual documents. These annotated documents can then be related to other structured information sources specified over similar ontologies.

In this paper we consider the processing of queries posed over multiple information resources that advertise their contents in terms of globally available, domain-specific ontologies. We describe a technique to identify the exact portion of a user's query that may not be answered by the set of available information agents. This is achieved by reasoning over the advertisements of the agents relative to the user's query. Our technique is based on the realization that the set difference of the queries q/sub 1/ and q/sub 2/ may be computed as a syntactic manipulation of the expressions q/sub 1/ and q/sub 2/ for a well defined subset of the relational algebra over a restricted class of relational schemas. That is to say, one may, without materializing data, take the expressions for q/sub 1/ and q/sub 2/ apply the query difference formula to yield q/sub 3/, and be guaranteed that q/sub 3/ is logically equivalent to q/sub 1/-q/sub 2/. With this query difference operator defined, the ability to compute query intersection, subsumption and equivalence follow. These claims are formally defined and proven and an example from an on-line movie guide domain is provided. In addition to the identification of missing resource agents, we anticipate a number of other applications of the query difference operator. This includes, but is not limited to, limiting the generality of dynamically constructed user queries, efficient query planning, and monitoring and controlling access to sensitive information.

The goal of the InfoSleuth project at MCC is to exploit and synthesize new technologies into a unified system that retrieves and processes information in an ever-changing network of information sources. InfoSleuth has its roots in the Carnot project at MCC, which specialized in integrating heterogeneous information bases. However, recent emerging technologies such as internetworking and the World Wide Web have significantly expanded the types, availability, and volume of data available to an information management system. Furthermore, in these new environments, there is no formal control over the registration of new information sources, and applications tend to be developed without complete knowledge of the resources that will be available when they are run. Federated database projects such as Carnot that do static data integration do not scale up and do not cope well with this ever-changing environment. On the other hand, recent Web technologies, based on keyword search engines, are scalable but, unlike federated databases, are incapable of accessing information based on concepts. In this experience paper, we describe the architecture, design, and implementation of a working version of InfoSleuth. We show how InfoSleuth integrates new technological developments such as agent technology, domain ontologies, brokerage, and internet computing, in support of mediated interoperation of data and services in a dynamic and open environment. We demonstrate the use of information brokering and domain ontologies as key elements for scalability.

Article Free Access Share on The InfoSleuth Project Authors: R. J. Bayardo Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile , W. Bohrer Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile , R. Brice Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile , A. Cichocki Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile , J. Fowler Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile , A. Halal Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile , V. Kashyap Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile , T. Ksiezyk Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile , G. Martin Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile , M. Nodine Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile , M. Rashid Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile , M. Rusinkiewicz Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile , R. Shea Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile , C. Unnikrishnan Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile , A. Unruh Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile , D. Woelk Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, Texas Microelectronics and Computer Technology Corporation (MCC), 3500 West Balcones Center Drive, Austin, TexasView Profile Authors Info & Claims SIGMOD '97: Proceedings of the 1997 ACM SIGMOD international conference on Management of dataJune 1997 Pages 543–545https://doi.org/10.1145/253260.253401Online:01 June 1997Publication History 7citation339DownloadsMetricsTotal Citations7Total Downloads339Last 12 Months2Last 6 weeks0 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

The basic transaction model has evolved over time to incorporate more complex transaction structures and to selectively modify the atomicity and isolation properties. In this paper we discuss the application of transaction concepts to activities that

To enforce global serializability in a multidatabase environment the multidatabase transaction manager must take into account the indirect (transitive) conflicts between multidatabase transactions caused by local transactions. Such conflicts are difficult to resolve because the behavior or even the existence of local transactions is not known to the multidatabase system. To overcome these difficulties, we propose to incorporate additional data manipulation operations in the subtransactions of each multidatabase transaction. We show that if these operations create direct conflicts between subtransactions at each participating local database system, indirect conflicts can be resolved even if the multidatabase system is not aware of their existence. Based on this approach, we introduce optimistic and conservative multidatabase transaction management methods that require the local database systems to ensure only local serializability. The proposed methods do not violate the autonomy of the local database systems and guarantee global serializability by preventing multidatabase transactions from being serialized in different ways at the participating database systems. Refinements of these methods are also proposed for multidatabase environments where the participating database systems allow schedules that are cascadeless or transactions have analogous execution and serialization orders. In particular, we show that forced local conflicts can be eliminated in rigorous local systems, local cascadelessness simplifies the design of a global scheduler, and that local strictness offers no significant advantages over cascadelessness.>

The multidatabase structured query language (MSQL) is an extension of the SQL query language that provides new functions for nonprocedural manipulation of data in different and mutually non-integrated relational databases. The problems introduced by these new functions are discussed, and the semantics of multiple updates, global commitment, and rollback are analyzed. New language constructs are developed to allow declarative specification of multidatabase transactions. The design and implementation of an environment for the execution of extended MSQL queries in a heterogeneous multidatabase environment are also discussed.>

In a research and technology application project at Bellcore, we used multidatabase transactions to model multisystem work flows of telecommunication applications. During the project a prototype scheduler for executing multi-database transactions was developed. Two of the issues addressed in this project were concurrent execution of multi-database transactions and their failure recovery. This paper discusses our use of properties of the application and the telecommunication systems to develop simple and efficient solutions to the concurrency control and recovery problems.

Soil maps and soil descriptions can be combined with other data sets within a geographical information system, to be used for analysis and modelling. As the amount of data to be included in such a database and the number of users of the database increase, the need for a structured approach to database design arises. In this paper, we discuss the conceptual design of a geographical database of soil information. We use an Extended Entity-Relationship (EER) model to capture the semantics and constraints of the database. The EER schema is then mapped into the relational data model. We show how the Structured Query Language (SQL) can be used to formulate sample queries that may be of interest to users of such a soil database. We also illustrate uses of the EER model in graphical formulation of database queries. Because of its high level of abstraction and intuitive simplicity, the EER model constitutes a convenient tool for both database design and formulation of database queries.

A global concurrency control mechanism for multidatabase systems that preserves the autonomy of local databases and is free from global deadlocks is presented. The mechanism extends the notion of timestamps to a multidatabase environment to enforce the global serialization order through additional data operations on a data item stored in local systems. The main advantage of the mechanism is that it allows a fully distributed architecture, in which concurrency control decisions can be made on the basis of locally available information. Since no centralized information is maintained by the mechanism, it provides a higher degree of fault tolerance and allows incremental growth.>

A model of nested transactions in distributed database systems is presented. The modeling approach is based on conflict serializability extended to accommodate multilevel transactions. Based on these definitions, serialization graph testing for nested transactions is discussed. Three concurrency control algorithms and proofs of their correctness are presented. The algorithms are an adaptation of serialization graph testing, an adaptation of the timestamp ordering protocol, and a variation of an optimistic protocol presented by H.T. Kung and J.T. Robinson (1981).>

In many application areas the information that may be of interest to a user is stored under the control of multiple, autonomous database systems. To support global transactions in a multidatabase environment, we must coordinate the activities of multiple Database Management Systems that were designed for independent, stand-alone operation. The autonomy and heterogeneity of these systems present a major impediment to the direct adaptation of transaction management mechanisms developed for distributed databases. In this paper we introduce a transaction model designed for a multidatabase environment. A multidatabase transaction is defined by providing a set of (local) sub-transactions, together with their precedence and dataflow requirements. Additionally, the transaction designer may specify failure atomicity and execution atomicity requirements of the multidatabase transaction. These high-level specifications are then used by the scheduler of a multidatabase transaction to assure that its execution satisfies the constraints imposed by the semantics of the application. Uncontrolled interleaving of multidatabase transactions may lead to the violation of interdatabase integrity constraints. We discuss the issues involved in a concurrent execution of multidatabase transactions and propose a new concurrency control correctness criterion that is less restrictive than global serializability. We also show how the multidatabase SQL can be extended to allow the user to specify multidatabase transactions in a nonprocedural way.

A multidatabase transaction management mechanism called the optimistic ticket method (OTM) is introduced for enforcing global serializability. It permits the commitment of multidatabase transactions only if their relative serialization order is the same in all participating local database systems (LDBSs). OTM requires the LDBSs to guarantee only local serializability. The basic idea in OTM is to create direct conflicts between multidatabase transactions at each LDBS in order to determine the relative serialization order of their subtransactions. A refinement of OTM, called the implicit ticket method (ITM), is also introduced that uses implicit tickets and eliminates ticket conflicts but works only when the participating LDBSs use rigorous transaction scheduling mechanisms. ITM uses the local commitment order of each subtransaction to determine its implicit ticket value. It achieves global serializability by controlling the commitment (execution order) and thus the serialization order of multidatabase transactions. Both OTM and ITM do not violate the autonomy of the LDBSs and can be combined in a single comprehensive mechanism.>

The class of transaction scheduling mechanisms in which the transaction serialization order can be determined by controlling their commitment order, is defined. This class of transaction management mechanisms is important, because it simplifies transaction management in a multidatabase system environment. The notion of analogous execution and serialization orders of transactions is defined and the concept of strongly recoverable and rigorous execution schedules is introduced. It is then proven that rigorous schedulers always produce analogous execution and serialization orders. It is shown that the systems using the rigorous scheduling can be naturally incorporated in hierarchical transaction management mechanisms. It is proven that several previously proposed multidatabase transaction management mechanisms guarantee global serializability only if all participating databases systems produce rigorous schedules.>

The design and implementation of an experimental fault-tolerant distributed database management system is described. The system provides a logically integrated view of data with distribution transparency and a controlled data replication. A commitment protocol used to guarantee atomicity of update operations is discussed. Efficient algorithms used to recover a site from a failure and restore data consistency are described. Recovery can be interleaved with the processing of regular database transactions and does not seriously limit the availability of data. The proposed solutions to the problems of fault recovery are designed to take advantage of the properties of a high-bandwidth local area network.>

A language is introduced in which both schema integration and query formulation for federated database systems can be performed. The relational model is augmented with connectors that impose predicate conditions over attributes of relations either at the same or different sites. The relational model with connectors has a natural diagrammatic representation, and thus, the language has a graphical user interface. The theoretical foundation for the graphical language is algebraic. Bach algebraic operator maps a diagram (of relations with connectors) into another diagram, and every diagram represents a possible user query. Operators specifically designed to operate on incompatible schemas are introduced and formally defined. Possible domain incompatibilities are resolved by using extended abstract data types.

The objectives and the general structure of a database management system designed for instructional use are described in this paper. Two high level interfaces which can be used to assist a student in query formulation are discussed. First of these interfaces is graphical and uses Macintosh microcomputer as a user's workstation. The other interface guides a student through the process of query formulation using a menu-driven approach. Preliminary experiences with these interfaces have shown that they can facilitate teaching of query formulation and help students to understand better the syntax and semantics of non-procedural query languages.

Extendible hashing addressing schemes have been introduced to resolve collisions and improve storage utilization by dynamically adjusting the address space and modifying the hash function. Recently, generalizations of extendible hashing have been proposed which allow multi-attribute keys to be used for improved partial-match query performance. In this paper the design and implementation of a multi-key extendible hashing access method for a relational DBMS is presented. The results of an experimental evaluation of performance of multi-key extendible hashing in a testbed relational DBMS suggest that for a wide class of queries it constitutes a viable alternative to ISAM-like files. The limitations of multi-key extendible hashing files and research problems which have to be solved before a practical access method for a relational DBMS can be developed are also discussed.

article Program transformations and their applications in teaching procedural and nonprocedural languages Share on Authors: Bogdan Czejdo Department of Computer Science, University of Houston, University Park, Houston, Texas Department of Computer Science, University of Houston, University Park, Houston, TexasView Profile , Marek Rusinkiewicz Department of Computer Science, University of Houston, University Park, Houston, Texas Department of Computer Science, University of Houston, University Park, Houston, TexasView Profile Authors Info & Claims ACM SIGCSE BulletinVolume 17Issue 1Mar. 1985 pp 202–210https://doi.org/10.1145/323275.323316Published:01 March 1985 0citation160DownloadsMetricsTotal Citations0Total Downloads160Last 12 Months0Last 6 weeks0 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteGet Access