P.J. McBrien and A. Poulovassilis. A uniform approachtointer-model transformations. In Proc. CAiSE'99, LNCS 1626, pages 333--348,19--3  Home/Search   Document Details and Download   Summary   Related Articles   Check

....nition of these constructs is separated by the de nition of constraints on their values. In this sense, the HDM is a low level model that underpins other data models. Higher level models either structured (e.g. E R, Relational, UML) or semi structured (e.g. XML) can be de ned in terms of the HDM [15, 16]. Thus, the HDM provides unifying semantics for higher level modeling constructs. Contribution. The main contributions of the paper are the following. We present a variation of the HDM for data source integration. The new model distin2 guishes between two kinds of nodes that model entities and ....

P. McBrien and A. Poulovassilis. A Uniform Approach to Inter-Model Transformations. In Proc. of the 11th Intl. Conf. on Advanced Information Systems Engineering, Springer-Verlag, LNCS No 1626, pages 333-348, 1999. 16

....that can link multiple nodes and other edges) and constraints. Schemas expressed using other data models may be regarded as representations of schemas of this CDM at a higher level. It is possible to translate any schema expressed using another data model into one expressed using this CDM (see [5]) Thus the local schemas of the local databases, that are expressed in whatever data model their respective databases may be employing, can be automatically transla ted into component schemas of the CDM. In this framework these component schemas are integrated into a global schema by means of ....

....of the software could even begin. It was necessary t o learn a relatively substantial volume of material connecting to the framework within which I was to work. I had to learn about the hypergraph data model. I had to learn how the automatically reversible schema transformations worked. 3] 4] [5], 6] 7] and [10] were all relevant to these goals) It was also necessary for me to understand the workings of the common query language (CQL) to be used (I used [8] Obviously, as well as reading I needed to spend a reasonable amount of time actually working through the mechanics of the ....

McBrien P and Poulovassilis A, "A uniform approach to inter-model transformations", Advanced Information Systems Engineering, 11th International Conference CAiSE'99, vo lume 1626, pages 333-348. Springer-Verlag, 1999.

....of data represented according to heterogeneous data models is a topic largely investigated in literature. We refer, in particular, to the recent works on the superimposed information models [14, 22] on the Model management systems [5, 6, 7, 9] and on the techniques for data conversion [9, 12, 23, 24, 25, 27]. In this framework, the goal of our current research (inspired by our previous work on management of multiple models in database design tools [2, 3] is the de nition of methods and techniques for the management of a wide variety of model based applications over the Web in a uniform way and to ....

P. McBrien and A. Poulovassilis. A Uniform Approach to Inter-model Transformations. In 11th Int. Conference on Advanced Information Systems Engineering (CAiSE99), Heidelberg, Lecture Notes in Computer Science 1626, Springer-Verlag, pages 333 348, 1999.

....are defined using the abstractions of the metamodel. Figure 3. An example of each of the three levels (model, schema, and instance) for XML. The definition of our superimposed information metamodel is similar to other metamodel approaches in the object [17, 18] and database communities [1 4, 5, 16] for describing structural models. Examples of structural models include the entity relationship model, the relational model, the hierarchical model, and the various semantic data models including the UML. 6 However, superimposed information models have a number of unique features that are ....

....share information. 6. Comparison of Related Work In this section, we discuss how our work compares to existing approaches for providing support for multiple models. A number of metamodels have been developed (see Atzeni and Torlone [1 4] Barsalou and Gangopadhyay [5] McBrien and Poulovassilis [16], and the Meta Object Facility [17] with the primary focus on supporting interoperability. Our metamodel is different from these approaches because we do not require model first nor schema first definitions. Rather, we support the independent specification of model, schema, and instance and we ....

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Peter McBrien and Alexandra Poulovassilis. A uniform approach to inter-model transformations. 11 th International Conference on Advanced Information Systems Engineering CAiSE'99, Lecture Notes in Computer Science Volume 1626, pages 333-348, Heidelberg, Germany, June 14-18, 1999.

....with each other and or with other structured data sources it is necessary in our view to employ a more elemental semantic data model as the common data model, rather than using XML itself. The approach that we present in this paper extends our previous work on integrating structured data sources [21, 18, 17]. In this work we have used as the common data model a low level hypergraph based data model (HDM) A set of primitive transformations is available for adding or deleting nodes, edges and constraints to 1 site function# sitecode account number customer cname for 1:1 0:N held by 1:1 0:N ....

....an attribute that forms part of a foreign key will be represented as a relationship while other relation attributes will be represented as attributes [4] Another advantage of using a low level common data model is that it provides a unifying semantics for higher level modelling constructs. In [18] we proposed a generic method for specifying the semantics of a higher level modelling language in terms of the HDM, showing how the set of primitive transformations for the language can then be automatically derived from this speci cation, and in this paper we will use the same method for ....

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P.J. McBrien and A. Poulovassilis. A uniform approach to inter-model transformations. In Advanced Information Systems Engineering, 11th International Conference CAiSE'99, volume 1626 of LNCS, pages 333-348. Springer-Verlag, 1999.

....of model, schema, and instance data for XML. Notice that we use an open DTD, which means that elements and attributes not defined in the DTD can be included in XML documents. The definition of our metamodel is similar to other metamodel approaches in the object [18, 19] and database communities [1 5, 17] for describing structural models such as the entity relationship model, the relational model, the hierarchical model, and the various semantic data models including the UML. However, we support a number of unique features with our metamodel. One such feature is the inclusion of marks, which are ....

....Instances XML XML DTD XML Document source target mapping converted converted Figure 17. Example of a model to schema mapping. 6 Comparison of Related Work A number of metamodels have been developed (see Atzeni and Torlone [1 4] Barsalou and Gangopadhyay [5] McBrien and Poulovassilis [17], and the Meta Object Facility [18] with the primary focus on supporting interoperability. Our metamodel is different from these approaches because we do not require model first nor schema first definitions. Rather, we support the independent specification of model, schema, and instance and we ....

[Article contains additional citation context not shown here]

Peter McBrien and Alexandra Poulovassilis. A uniform approach to inter-model transformations. 11 th International Conference on Advanced Information Systems Engineering CAiSE'99, Lecture Notes in Computer Science Volume 1626, pages 333-348, Heidelberg, Germany, June 14-18, 1999.

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McBrien, P., Poulovassilis, A.: A uniform approach to inter-model transformations. In: Advanced Information Systems Engineering, 11th International Conference CAiSE'99, Heidelberg, Germany. Volume 1626 of Lecture Notes in Computer Science., Springer (1999) 333--348

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P.J. McBrien and A. Poulovassilis. A uniform approachtointer-model transformations. In Proc. CAiSE'99, LNCS 1626, pages 333--348, 1999.

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P.J. McBrien and A. Poulovassilis. A uniform approachtointer-model transformations. In Proc. CAiSE'99, LNCS 1626, pages333-- 1999.

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P.J. McBrien and A. Poulovassilis. A uniform approach to inter-model transformations. In Advanced Information Systems Engineering, 11th International Conference CAiSE'99, volume 1626 of LNCS, pages 333--348. Springer-Verlag, 1999.

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P. McBrien and A. Poulovassilis. A uniform approach to inter-model transformations. In LNCS, volume 1626, pages 333--348. Springer-Verlag, June 1999.

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P.J. McBrien and A. Poulovassilis. A uniform approachtointer-model transformations. In Proc. CAiSE' LNCS 1626, pages 333--348, 1999. 24

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P. McBrien and A. Poulovassilis. A uniform approach to intermodel transformations. In Proc. CAiSE'99, pages 333--348, 1999.

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P. McBrien and A. Poulovassilis. A uniform approach to inter-model transformations. In Proc. CAiSE'99, LNCS 1626, pages 333--348, 1999.

....relational) as the common data model can be complicated because the original and transformed schemas may be represented in different high level modelling languages and there may not be a simple semantic correspondence between their modelling constructs. In previous work within the AutoMed project [8, 9, 10], a general framework has been developed to support schema transformation and integration. This framework provides a lowerlevel hypergraph based data model (HDM) as the common data model and a set of primitive schema transformations for schemas defined in this data model. One advantage of using a ....

....for schemas defined in this data model. One advantage of using a low level data model such as the HDM is that semantic mismatches between modelling constructs are avoided. Another advantage is that it provides a unifying semantics for higher level modelling constructs. In particular, [10] shows how ER, relational and UML data models, and the set of primitive schema transformations on each of them, can be defined in terms of the lower level HDM and its set of primitive schema transformations. That paper also discusses how inter model transformations are possible within the AutoMed ....

[Article contains additional citation context not shown here]

McBrien, P., Poulovassilis, A.: A uniform approach to inter-model transformations. In: Advanced Information Systems Engineering, 11th International Conference CAiSE'99, Heidelberg, Germany. Volume 1626 of Lecture Notes in Computer Science., Springer (1999) 333--348

....transforma tions are conditional upon. One advantage of using a low level common data model such as the HDM is that semantic mismatches between modelling constructs are avoided. Another advantage is that it provides a unifying semantics for higher level modelling constructs. In particular, in [18] we described how our framework can be applied to different high level modelling languages such as relational, ER and UML. In [19] we showed how XML data sources can also be handled within our framework. 2.1 A simple relational data model For our purposes in the present paper, we assume that all ....

P. McBrien and A. Poulovassilis. A uniform approach to inter-model transformations. In Proc. CAiSE'99, LNCS 1626, pages 333-348, 1999.

....due to variations in schema design for the same universe of discourse. Logical integration requires facilities for transforming and integrating a set of source schemas into a global schema, and for translating queries posed on the global schema to queries over the source schemas. In previous work [14, 15, 19, 17, 16] we have developed a general frame work which provides these facilities. In this paper we consider the problem of evolving the global schema, and repairing the query translation pathways, as source schemas evolve. Other heterogeneous database systems, such as TSIMMIS [6] InterViso [22] IM ....

....repair of global schemas as source schemas evolve. Much of the previous work on schema evolution has presented approaches in terms of just one data model e.g. 1, 4, 5, 11] In contrast, we represent higher level data modelling languages in terms of an underlying hypergraph based data model [17]. Thus, the techniques for handling source schema evolutions that we propose in this paper can be applied to any of the common data modelling languages. In [12] it was argued that a uniform approach to schema evolution and schema integration is both desirable and possible, and this is our view ....

[Article contains additional citation context not shown here]

P.J. McBrien and A. Poulovassilis. A uniform approach to inter-model transformations. In Advanced Information Systems Engineering, 11th International Conference CAiSE'99, volume 1626 of LNCS, pages 333-348. Springer-Verlag, 1999.

....work within the Automed project [18, 12] a general framework has been developed to support schema transformation and integration. This framework consists of a low level hypergraph based data model (HDM) and a set of primitive schema transformations defined in terms of this lower level model. [13] gives the definitions of equivalent HDM representations for ER, relational and UML schemas, and discusses how inter model transformations can be supported via this underlying common data model. The approach is extended to also encompass XML data sources in [14] and current work in Automed is ....

....In this paper we show how Automed s transformation pathways can also be used to trace the lineage of data in a data warehouse which integrates data from several sources. We assume that both the source schemas and the integrated schema are expressed in the HDM data model since, as discussed in [13], higherlevel schemas and transformations between them can be automatically translated into an equivalent HDM representation. We use a functional intermediate query language (IQL) for expressing the semantic relationships between schema constructs in transformations. The remainder of this paper ....

[Article contains additional citation context not shown here]

P. McBrien and A. Poulovassilis. A uniform approach to intermodel transformations. In Proc. CAiSE'99, pages 333--348, 1999.

....due to variations in schema design for the same universe of discourse. Logical integration requires facilities for transforming and integrating a set of source schemas into a global schema, and for translating queries posed on the global schema to queries over the source schemas. In previous work [14, 15, 19, 17, 16] we have developed a general framework which provides these facilities. In this paper we consider the problem of evolving the global schema, and repairing the query translation pathways, as source schemas evolve. Other heterogeneous database systems, such as TSIMMIS [6] InterViso [22] IM [13] ....

....repair of global schemas as source schemas evolve. Much of the previous work on schema evolution has presented approaches in terms of just one data model e.g. 1, 4, 5, 11] In contrast, we represent higherlevel data modelling languages in terms of an underlying hypergraph based data model [17]. Thus, the techniques for handling source schema evolutions that we propose in this paper can be applied to any of the common data modelling languages. In [12] it was argued that a uniform approach to schema evolution and schema integration is both desirable and possible, and this is our view ....

[Article contains additional citation context not shown here]

P.J. McBrien and A. Poulovassilis. A uniform approach to inter-model transformations. In Advanced Information Systems Engineering, 11th International Conference CAiSE'99, volume 1626 of LNCS, pages 333--348. Springer-Verlag, 1999.

....than to use XML itself. Note that this does not preclude the use of XML as the data transfer mechanism, just that the modelling of multiple data sources requires something more structured. The approach that we present in this paper extends our previous work on integrating structured data sources [20, 16, 15]. In this work, we have used as the common data model a low level hypergraph based data model (HDM) One advantage of this HDM is that it separates the definition of the data sets from the definition of constraints on the values of these data sets. All data is held as either nodes representing ....

....languages and primitive schema transformations for those languages are defined in terms of this lower level HDM and its primitive transformations. Hence another advantage of using a low level common data model is that it provides a unifying semantics for higher level modelling constructs. In [16] we proposed a generic method for specifying the semantics of a higher level modelling language in terms of the HDM, showing how the set of primitive transformations for the language can then be automatically derived from this specification. Transformations on higher level modelling languages can ....

[Article contains additional citation context not shown here]

P.J. McBrien and A. Poulovassilis. A uniform approach to inter-model transformations. In Advanced Information Systems Engineering, 11th International Conference CAiSE'99, volume 1626 of LNCS, pages 333--348. Springer-Verlag, 1999.

....transformation can be found in [14] The Hypergraph Data Model and the primitive transformations for it were first introduced in [17] where we showed how CoopIS00 Paper P82 4 higher level modelling languages and schema transformations for them can be defined in terms of this lower level HDM. In [16] we developed a generic method for defining the semantics of higher level modelling languages in terms of the HDM, showing how the set of primitive schema transformations for such higher level modelling languages can then be automatically derived. These transformations can be used to map between ....

....(manager(X) staff(X) 1 delNode manager(X) man (X,true) 25 contractEdge staff#works in#dept 26 contractEdge dept#part of#division 27 contractNode dept end We can now handle the last three contraction steps 25 27 as in Section 3.3. 4 Schemas using Higher Level Modelling Constructs In [16] we showed how higher level modelling languages can be expressed using the low level constructs of the HDM. This is illustrated in Figure 5 which shows three higher level schemas and an HDM schema. The constructs of the three higher level modelling languages (ER, UML and relational) are ....

[Article contains additional citation context not shown here]

P.J. McBrien and A. Poulovassilis. A uniform approach to inter-model transformations. In Advanced Information Systems Engineering, 11th International Conference CAiSE'99, volume 1626 of LNCS, pages 333--348. Springer-Verlag, 1999.

....than to use XML itself. Note that this does not preclude the use of XML as the data transfer mechanism, just that the modelling of multiple data sources requires something more structured. The approach that we present in this paper extends our previous work on integrating structured data sources [19, 15, 14]. In this work, we have used as the common data model a low level hypergraph based data model (HDM) One advantage of this HDM is that it separates the definition of the data sets from the definition of constraints on the values of these data sets. All data is held as either nodes representing ....

....languages and primitive schema transformations for those languages are defined in terms of this lower level HDM and its primitive transformations. Hence another advantage of using a low level common data model is that it provides a unifying semantics for higher level modelling constructs. In [15] we proposed a generic method for specifying the semantics of a higher level modelling language in terms of the HDM, showing how the set of primitive transformations for the language can then be automatically derived from this specification. Transformations on higher level modelling languages can ....

[Article contains additional citation context not shown here]

P.J. McBrien and A. Poulovassilis. A uniform approach to inter-model transformations. In Advanced Information Systems Engineering, 11th International Conference CAiSE'99, volume 1626 of LNCS, pages 333--348. Springer-Verlag, 1999.

....models. It can also be used to help handle changes in source databases: if a change of a database schema S to a schema S 0 is represented by a transformation from S to S 0 then any query that previously was used on S can be automatically translated to a query on S 0 . In more recent work [11], we have developed a generic framework for de ning the semantics of higher level modelling language constructs in terms of the HDM. The de nitions of the higher level primitive transformations are then automatically derived. In that paper we also show how these transformations can be used to map ....

P.J. McBrien and A. Poulovassilis. A uniform approach to inter-model transformations. In Advanced Information Systems Engineering, 11th International Conference CAiSE'99, volume 1626 of LNCS, pages 333-348. Springer-Verlag, 1999.

No context found.

P.J. McBrien and A. Poulovassilis. A uniform approachtointer-model transformations. In Proc. CAiSE'99, LNCS 1626, pages 333--348,19--3

No context found.

P. McBrien and A. Poulovassilis. A uniform approach to inter-model transformations. In Advanced Information Systems Engineering, 11th International Conference CAiSE'99, Heidelberg, Germany, volume 1626 of Lecture Notes in Computer Science, pages 333--348. Springer, 1999.

No context found.

P.J. McBrien and A. Poulovassilis. A uniform approach to inter-model transformations. In CAiSE'99, volume 1626 of LNCS, pages 333-348. Springer-Verlag, 1999.

No context found.

P. McBrien and A. Poulovassilis. A uniform approach to inter-model transformations. In Proc. CAiSE99, pages 333--348, 1999.

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