Moira C. Norrie. An extended entity-relationship approach to data management in object-oriented systems. In Proceedings of the 12th International Conference on Entity-Relationship Approach, 1993.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....in the sketch framework, the arrow h is nothing but another visualization of the commutativity marker h=i. Another similar example. Boolean operations and relations on sets are often required to be denoted in semantic schemas. Various notational systems were proposed, one of them, taken from [23], is depicted on schema (q) The circled c stands for covering, that is, to denote that the set Y is the union of sets A and B. The circled i means that X is the intersection of A and B. So, the diagram (q) represents some arrow diagram property: its shape is the square diagram depicted on ....

M. Norrie. An extended entity-relationship approach to data management in object-oriented systems. In 12th Int.Conf. on Entity-Relationship Modeling, ER'95, Springer LNCS'823, pages 390--401, 1993.

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Moira C. Norrie. An extended entity-relationship approach to data management in object-oriented systems. In Proceedings of the 12th International Conference on Entity-Relationship Approach, 1993.

....file. In Fig. 3, we show such a mapping and model this as an association Binds between a set of ResourceIds and a set of Resources.Using normal barcode reader technology, we could play video files when the user swipes or points at the barcode with the reader. Note that we are using the OM model [14, 16] since the information servers for interactive paper that we have developed are based on this model and its associated OMS data management frameworks [12, 24] The OM model has a collection construct (represented by the shaded rectangles) to represent semantic groupings of objects and associations ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems. In Proceedings of ER'93, 12th International Conference on the Entity-Relationship Approach, Arlington, USA, December 1993.

....appropriate servlet. For example, we show servlets to handle requests from HTML browsers, WAP phones in terms of WML browsers and voice telephones in terms of VXML (VoiceXML) The underlying database management system is OMS Java, an object oriented data management system based on the OM model [8]. The OM model is a generic, semantically rich model that distinguishes typing and classification of objects and includes support for managing associations between objects. It is beyond the scope of this paper to describe the OM model and OMS Java in detail. Further details of OMS Java can be ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems. In Proceedings of ER'93, 12th International Conference on the Entity-Relationship Approach, Arlington, USA, December 1993.

....data model on which both the framework and application design are based. This data model must therefore be both semantically expressive to aid the application developer and also amenable to e#cient, platform independent implementation. The OMS Java framework is based on the OM object data model [Nor93,Nor95] which is a generic collection based model o#ering a rich set of collection constructs and also a powerful collection algebra. The model combines features of entity relationship and object oriented models, but it is important to note that in contrast to many of these it also has a full ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in ObjectOriented Systems. In 12th Intl. Conf. on Entity-Relationship Approach, pages 390--401, Dallas, Texas, December 1993. Springer-Verlag, LNCS 823.

....on object oriented and Web technologies. OMS supports all stages of information system development from conceptual modelling through design to implementation. All stages are based on the same abstract model of the application domain as modelled in the semantically rich OMS object data model, OM [17]. OM supports information modelling through a two level structure of classification and typing [18] Entities are classified into one or more collections corresponding to their roles and these collections are part of a classification graph specifying role dependencies. Role dependent object views ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems. In 12th Intl. Conf. on Entity-Relationship Approach, pages 390--401, Dallas, Texas, Dec. 1993. Springer-Verlag, LNCS 823.

....is the core of the XD framework described in section 3. 2 The eXtreme Design Meta Model With the eXtreme Design (XD) meta model [Kob01] shown in Figure 1, it is possible to specify abstract data types on a very high level of abstraction. The model itself is defined in terms of the OM model [Nor93, Nor95] making it possible to easily customise the XD meta model by adding, for example, new collections and associations. 1 attribute objectGroup object method valueEntity Object Groups Attributes Methods Value Entities are member of 0: 0: refer to 0: 0: are specified by ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems. In 12th Intl. Conf. on Entity-Relationship Approach, pages 390--401, Dallas, Texas, December 1993. Springer-Verlag, LNCS 823.

....most dicult to implement. The database system has to o er an API which can be used to implement a server according to the agent s needs. It is obvious that there has to exist a server for every di erent DBMS to be supported. We instead developed a prototype using the OMS Java system described in [NW97a, NW97b, Nor93, KN99] which is itself built in a manner that the underlying storage system is exchangeable. In this way, we achieved our goal of being independent of a particular storage system. The prototype system is described in section 4. As described previously, the data to store consists of application data and ....

....of the system and the work ow between them. WWW Pages User Info querying browsing ACADEMIA Database searching consultations settings storing Agent CADEMIA A Figure 3: The components of Academia The Academia database is implemented using the OMS object oriented DBMS described in [NW97a, NW97b, Nor93]. The OMS system is a perfect example of a database which meets our preferences. It provides a graphical browser, a full query language and methods which support the various operations of the user such as the downloading of documents through ftp. Since the system also supports URLs as a base type, ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems. In Proc. of the 12th Intl. Conference on EntityRelationship Approach, Arlington, Texas, December 1993.

.... to ODMG based ones such as ObjectStore PSE Pro (www.odi.com) and Objectivity DB (www.objy.com) and to proprietary systems such as Berkley DB (www.sleepycat.com) Further, OMS Java provides a high level of application data abstraction through its support for the generic object model OM [Nor95, Nor93] which is conceptually expressive and a good framework for managing complex object structures together with their associations. In Section 2 we introduce the generic object model OM which is the core data model of OMS Java. An overview of the OMS Java framework is given in Section 3 and Section ....

.... intersect Subcollection Constraints over Subcollections Figure 3: Classification structures It is beyond the scope of this paper to describe all aspects of the OM model. More detailed descriptions of the OM model and also other systems based on the model can be found in [KNW98, NW97, Nor95, Nor93] 3 OMS Java OMS Java (Object Model System for Java) SKN98] can be considered both as a multi tier object oriented database management system and as an object oriented application framework for the Java environment. OMS Java supports the object data model OM [Nor95, Nor93] presented in section ....

[Article contains additional citation context not shown here]

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems. In 12th Intl. Conf. on Entity-Relationship Approach, pages 390--401, Dallas, Texas, December 1993. Springer-Verlag, LNCS 823.

....protocol, any system allowing general Web access can access the database and there are no special problems of security restrictions especially in the case of networks controlled by firewalls. Due to these advantages, we also provide such an interface as part of the OMS database development suite [Norrie 93, Wuergler 95, Leidi et al. 98] to facilitate universal Web access to OMS databases. The disadvantage of this approach is that the entire processing of requests is on the server side. This includes the processes of handling HTTP requests, constructing queries to be executed and communicating with ....

....approach based on the idea of extending the DBMS with Web components that execute on the client machine and are accessed through a general Web browser. The system was built to investigate means of providing fast and effective Web access to databases and is based on our own OODBMS called OMS [Norrie 93, Wuergler 95] The architecture of Internet OMS is shown in figure 3. The architecture can be viewed in terms of its server and client sides with the browser part considered as the user s entry point to the Internet database. On the server side there is the OMS System with the OMS Server on top, ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object Oriented Systems. In 12th Intl. Conf. on Entity Relationship Approach, pages 390--401, Dallas, Texas, December 1993. Springer-Verlag, LNCS 823.

....A particular type model may restrict the type graph and inheritance mechanisms but, at the OM level, we do not assume any such restrictions. The model also has support for, and controls over, object evolution. Information on the OM algebra and further details of the OM model are given in [9, 8, 7]. The operational part of OM introduces a set of operations over collections in terms of a collection algebra. The OM model also allows collections of different behaviors as arise in many OODBMS. The behavior is denoted by a collection s bulk type: beside set behavior, a collection may have ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems. In 12th Intl. Conf. on Entity-Relationship Approach, pages 390--401, Dallas, Texas, December 1993. Springer-Verlag, LNCS 823.

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Norrie M.C. (1993) An Extended EntityRelationship Approach to Data Management in Object-Oriented Systems. Proc. of the 12th Intl. Conference on Entity-Relationship Approach, Arlington, Texas.

....as a link between the Core System and the Configuration Component The following sections describe in more detail how OMS Java has been extended to support the Temporal Object Data Model TOM [SN97c, SN97a] 5. 1 The Temporal Object Data Model TOM TOM is based on the generic object data model OM [Nor93] and exhibits many of the features found in various temporal object oriented models, e.g. RS91, WD93, KS92, BFG96] but in a more generalized form. For example, we timestamp not only data values, but also collections of objects and the associations containing the temporal relationships ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems. In Proceedings of the 12th International Conference on the ER Approach, 1993.

....the request to its neighbours if no corresponding entry is found in its routing table. The routing tables are dynamically updated from the DOIDS which can be managed through a GUI administrator tool. There are a number of features of the OMS System [5, 8, 9] and its underlying data model OM [6] that make it particularly suited to distribution and sharing of both schema and data. Most important is that all information both data and metadata is represented as objects and this allows both schema and data to be handled uniformly with regard to distribution and sharing. Every OMS ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems. In 12th Intl. Conf. on Entity-Relationship Approach, pages 390--401, Dallas, Texas, December 1993. Springer-Verlag, LNCS 823.

....histories. TOM also supports a full temporal algebra, query language and constraints. Additionally, metadata can have temporal properties allowing the modelling of role, association and constraint lifespans. Our temporal object data model is based on the generic object oriented data model, OM [Nor93] The OM model strictly separates typing from classification in such a way that classification structures model the roles of objects rather than their representation. The model is therefore independent of any particular type system and programming language environment. Other key features of the ....

....over migration are discussed in detail in [NSWW96] The operational model of OM is based on an algebra of collections. Descriptions of some of these operations are given in section 5 where the temporal equivalents are described. Further details of the OM model and its algebra are given in [Nor93] We have developed our own object oriented database management system, OMS, based on the OM model. An interesting aspect of the OMS system with respect to temporal generalisation is its representation of all information both data and metadata as objects. Our approach of generalising ....

[Article contains additional citation context not shown here]

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems. In Proceedings of the 12th International Conference on the ER Approach, 1993.

No context found.

Norrie M.C. (1993) An Extended EntityRelationship Approach to Data Management in Object-Oriented Systems. Proc. of the 12th Intl. Conference on Entity-Relationship Approach, Arlington, Texas.

....developed object oriented data models are much more appropriate for these sorts of applications and the goal of our project is to provide Oberon programmers with the constructs and functions needed to support such a model. In order to realize this goal, we adapted the OM generic object data model [7] and made it available to the programmer through a set of Oberon modules. Since our primary goal is to provide Oberon programmers with database programming support, it was a basic requirement that no change be made to the Oberon 2 language [12] and minimum changes to the run time system. This we ....

....subPapers.SetObjectAttribute(paper, submissionDate , dateAttr) END SubmitPaper; 3 The Algebra In the past, one of the main criticisms made against object oriented database systems was their lack of an associated algebra and query language. In this section, we present an algebra, based on [6] [7], in which the operations on collections of our model are defined. Algebra operations always generate collections of objects. For other operations such as aggregation, the user has to write specific Oberon code. For example, if we are interested in the number of papers written by a given author, ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in ObjectOriented Systems. In 12th Intl. Conf. on Entity-Relationship Approach, pages 390--401, Dallas, Texas, December 1993. Springer-Verlag, LNCS 823.

....temporal constructs into the system and query language. We start by describing the main features of our temporal object model and then, by means of examples, introduce the system and its query language. Our temporal object data model, TOM, is based on the generic object oriented data model, OM [Nor93] and exhibits many of the features found in various temporal object oriented models, e.g. RS91, WD93, KS92, BFG96] but in a more generalized form, as we will demonstrate in this paper. The OM model strictly separates typing from classification in such a way that classification structures model ....

....union, intersection and difference. There are also operations to map a given function over a collection, to select elements of a collection based on a predicate condition and to flatten a collection of collections by eliminating one level of nesting. A full description of the algebra is given in [Nor93, Nor92] The TOM model specifies temporal equivalents for these operations. There are only two operations which refer to type information or attribute values, namely the projection (special case of map) and selection operations. All other operations do not refer to any attribute values and work ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in ObjectOriented Systems. In Proceedings of the 12th International Conference on the ER Approach, 1993.

....rich classification structures with constraints such as exclusion and totality over collections of objects. We have based our global model on NIAM [VB82, Win89] but note that an object data model with a relationship construct and classification constraints would be equally suitable (e.g. Nor92, Nor93] The lack of support for the modelling of relationships in EXPRESS [EXP92] makes it less suitable; however, the addition of relationship constructs are being considered for the new standard, E EXPRESS. A Coordination Agent also has to respond to actions delegated by the Global Coordinator. The ....

....all released manuals. In this way, object type in the sense of NIAM has both an intensional and an extensional notion similar to the use of entity types or entity sets in the entity relationship family of data models (see for example, EN94] This differs from those object data models, such as [Nor93] which clearly distinguish the two notions through distinct notions of typing and classification. A detailed discussion of advantages in distinguishing the intensional and extensional notions in object data models is given in [Nor95] As used in our approach, object type is primarily considered ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems. In 12th Intl. Conf. on Entity-Relationship Approach, pages 390--401, Dallas, Texas, December 1993. Springer-Verlag, LNCS 823.

....and research database management systems (DBMS) the task of providing Internet access to databases and their application services is relatively straightforward. For example, the commercial systems Oracle [Ora96] and O 2 [O2 ] and our own research object oriented data management system OMS [Nor93, Wue95, EN97a] all provide WWW Interfaces. However, given the typical delays in WWW access to information currently experienced, it is another step to ensure an effective information service in terms of performance and user satisfaction. In spite of efforts to improve network communications, ....

....This personal assistant maintains the user profile and cooperates with the other agents to increase the prefetching of data according to observed behaviour patterns. Using this framework, we have developed a number of Internet information systems based on our object oriented database system, OMS [Nor93, Wue95] and its WWW interface [EN97a] These include an Internet brokering system for engineering product data (IPBS) an integrated tourist information service for snow and avalanche data in the Swiss Alps [EN97b] and an information system for renting holiday apartments. In this paper, we will ....

[Article contains additional citation context not shown here]

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems. In 12th Intl. Conf. on Entity-Relationship Approach, pages 390--401, Dallas, Texas, December 1993. Springer-Verlag, LNCS 823.

....system to allow users to access the data through a single entry point using a WWW browser. WWW interfaces are now available for a number of database management systems (DBMS) including, the commercial systems Oracle [Ora96] and O 2 [O2 ] and our own research prototype object oriented DBMS, OMS [Nor93, Wue95] It is not a major problem anymore to provide Internet access to existing databases. The problem is to provide it in an effective way, such that the requirements of regular users can be met without the typical delays currently experienced using Internet browsers and the WWW. Even for ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Sy stems. In 12th Intl. Conf. on Entity-Relationship Approach, pages 390--401, Dallas, Texas, December 1993. Springer-Verlag, LNCS 823.

....will provide its own GUI. In figure 2, we see that not only the user, but also other applications can use IDEOMS by accessing it directly. For example, a CASE tool could be constructed on top of IDEOMS. OMS was developed at ETH Zurich and is based on the generic object data model OM described in [Nor93] which specifies constructs and operations for the management of interrelated collections of objects. The OM model is generic in that it is independent of the form of individual objects and hence of the underlying type model and programming language system. The model is instantiated in terms of ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems. In 12th Intl. Conf. on Entity-Relationship Approach, pages 390--401, Dallas, Texas, December 1993. Springer-Verlag, LNCS 823.

.... 11111111111111 11111111111111 11111111111111 Database searching consultations settings storing Agent CADEMIA A Figure 1: The components of Academia The Academia database is implemented using the OMS object oriented database management system (DBMS) described in [ Norrie and Wurgler, 1997; Norrie, 1993 ] OMS provides a graphical browser, full query language and methods which are used to support user operations such as downloading documents. Since the system also supports URLs as a base type, viewing Web pages and sending email via an Internet browser can be done directly from OMS. Further, ....

M. C. Norrie. An Extended EntityRelationship Approach to Data Management in Object-Oriented Systems. In Proc. of the 12th Intl. Conference on Entity-Relationship Approach, Arlington, Texas, December 1993.

....7: Example Schema Diagram Note that classification constraints over collections isa, disjoint, cover, partition and intersection apply to both unary and binary collections. Both OM and OM also have an operational part which specifies an algebra over collections based on that described in [Nor93b] In OM , all of the operations of OM are incorporated and these apply to both unary and binary collections. In addition, some operations are specific to binary collections; they utilise the fact that the elements of the collections are pair values. As a result, relations can be operated on as ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems. In 12th Intl. Conf. on Entity-Relationship Approach, Dallas, Texas, December 1993.

....it has been recognised by a number of researchers that the internalisation of relationships is a major drawback of object data models and as a result there are now a number of proposals to extend object data models with direct support for relationships. These include [AGO91, Bra90, DG90, HN91, Nor93a, NQZ90, Rum87] These models have been designed to redress the imbalance between the notions of entities and relationships that exist in most object data models. Through the addition of a relationship construct, it is possible to combine object oriented technologies with the conceptual modelling ....

....can translate into a physical model in which the object data management services manage collections of object references rather than the objects themselves. The management of objects in terms of their storage and access is the responsibility of the persistent object store. The Collection Model [Nor93a] is an example of such a generic object data model. Essentially, the Collection Model can be likened to the object data model OM without the type constructs. However, it does support both set and bag collections and slightly different forms of classification structure. This model forms the basis ....

M. C. Norrie. An Extended Entity-Relationship Approach to Data Management in Object-Oriented Systems. In 12th Intl. Conf. on Entity-Relationship Approach, pages 390--401, Dallas, Texas, December 1993. Springer-Verlag, LNCS 823.

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