S. Spaccapietra and C. Parent. View Integration : A Step Forward in Solving Structural Conflicts. TKDE, 6(2):258--274, 1994.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....or some other way These cases of differing representations between input models are called conflicts. For the most part, conflict resolution is independent of the representation of A and B. Yet most work on merging schemas is data modelspecific, revisiting the same problems for ER variations [19], XML [3] data warehouses [7] semi structured data [4] and relational and object oriented databases [6] Note that these works, like ours, consider merging only the models, not the instances of the models. Some models, such as ontologies and ER diagrams, have no instance data. First Name ....

....also specify property values. For example, in Figure 2 MapAB specifies that one of the elements contained by AllBios is named Official and the other is named Unofficial. Solving representation conflicts has been a focus of the ontology merging literature [14, 15] and of database schema merging [2, 19]. 3.2 Meta model Conflicts A meta model conflict occurs when the merge result violates a meta model specific (e.g. SQL DDL) constraint. For example, suppose that in Figure 2 Actor is a SQL table in model A, an XML database in model B, and a SQL table in the merged model. If the mapping in ....

[Article contains additional citation context not shown here]

Spaccapietra, S. and Parent, C. View Integration: A Step Forward in Solving Structural Conflicts. TKDE, 6(2).

....and transformation. Obviously in information systems, it is in general easier to integrate or align the conceptual models of the systems than to integrate the logical or the physical internal representation of the system, as demonstrated by the literature on view and schema integration (e.g. [SP94]) Therefore, ORM ML as a standardized syntax for ORM models may assist interoperation tools to exchange, parse understand the ORM schemes. 3. Defining ORM Markup Language This section describes the main elements of the ORM ML grammar and demonstrates it using a few selected short examples. The ....

S. Spaccapietra, C. Parent, "View Integration: A Step Forward in Solving Structural Conflicts", IEEE Transactions on Data and Knowledge Engineering 6(2), IEEE, 1994.

....and transformation. In information systems, it is in general easier to integrate or align the conceptual models of the systems than to materially integrate the logical or the physical internal representation of the system, as demonstrated by the literature on view and schema integration (e.g. [SP94]) Therefore, ORM ML as a standardized syntax for ORM models may assist interoperation tools to exchange, parse or understand the ORM schemas. Interoperability for exchanging and sharing conceptual models over the Internet. Facilities are needed to share and exchange ORM conceptual models ....

S. Spaccapietra, C. Parent, "View Integration: A Step Forward in Solving Structural Conflicts", IEEE Transactions on Data and Knowledge Engineering 6(2), IEEE, 1994.

....cases of differing representations between input models are called conflicts. For the most part, conflict resolution is independent of how A and B are represented. Yet most work on merging schemas concentrates on doing it in a data model specific way, revisiting the same problems for ER variations [30], XML [4] data warehouses [11] semistructured data [5] or relational and object oriented databases [10] Note that these works, like ours, consider merging only the models, not the instances of the models. Some models, such as ontologies and ER diagrams, have no instance data, and merging the ....

....the merged model contains all of the objects in the two original models, 2) reconcile representation conflicts in the views (e.g. if a table in one view is matched with a column in another) and (3) require user input to guide the merge. Spaccapietra and Parent have a well known algorithm [30] that consists of a set of rules and a prescribed order to apply them in. Their meta meta model, ERC , has three different object types: attributes, entities, and relations. An entity is an object that is of interest on its own. An attribute describes data that is only of interest while the object ....

Spaccapietra, S. and Parent, C. View Integration: A Step Forward in Solving Structural Conflicts. TKDE, 6(2).

....that can be studied as challenges for the model management operators. This literature is too large to cite here, but we can highlight a few areas where there is obvious synergy worth exploring. Some of them were mentioned earlier: schema matching (see the survey in [23] schema integration [1,8,15,25], which is both an example and a source of algorithms for Match and Merge; and adding semantics to mappings [7,17,21,27] Others include: Data translation [24] Differencing [11,19,26] and . EER style representations and their expressive power, which may help select the best representation ....

Spaccapietra, Stefano and Christine Parent. View integration: A step forward in solving structural conflicts. TKDE 6(2): 258-274 (April 1994).

....all new buildings (S1.Buildings not specialized to old buildings) are included in the second database as habitable buildings. S1.Building: S1.Old Building: S2.Building: S2.Habitable Building: 1 2 3 4 5 Figure 2: Extensional Overlapping of Input Classes Most existing integration approaches [13, 12, 21, 3, 7, 22, 15, 8, 14] do only mark pairs of classes with a possibly non empty population intersection as candidates for integration. Additionally, attributes may be marked to be corresponding. The resulting integration assertions can be listed in the notation proposed by [22] S1fflBuilding S2fflBuilding ....

....approaches [13, 12, 21, 3, 7, 22, 15, 8, 14] do only mark pairs of classes with a possibly non empty population intersection as candidates for integration. Additionally, attributes may be marked to be corresponding. The resulting integration assertions can be listed in the notation proposed by [22]: S1fflBuilding S2fflBuilding Attribute correspondence: S1fflBuildingfflAddress j S2fflBuildingfflAddress S1fflBuilding S2fflHabitable Building Attribute correspondence: S1fflBuildingffl#flats j S2fflHabitable Buildingffl#flats S1fflOld Building S2fflBuilding Attribute ....

S. Spaccapietra and P. Parent. View Integration: A Step Forward in Solving Structural Conflicts. IEEE Transactions on Knowledge and Data Engineering, 6(2):258--274, April 1994.

....any instance of a general engineering activity. For instance, several database design methodologies have been proposed so far, ranging from standard ERA based approches to the more recent OO approaches. Less common activities such as database reverse engineering [HAI,93a] or schema integration [SPACCA,92] have been formally described through specific methodologies as well. Describing methodologies relates to (software design) process modelling, a discipline that is concerned with the understanding, representation and computer based support of the software engineering activities [POTTS,88] ....

Spaccapietra, S., Parent, C., View Integration : A Step Forward in Solving Structural Conflicts, IEEE Trans. on Knowledge and Data Engineering, October, 1992

.... to formalize nature of the subject and leads to an abundance of ad hoc solutions and methodologies (see also [9] A lot of approaches to classifying and managing structural conflicts were proposed ( 3, 1, 8, 12] and others) the most fundamental to date research is that one by Spaccapietra et al. ([14, 13]) where a taxonomy distinguishing semantic, descriptional, structural and heterogeneity conflicts was suggested. However, the taxonomy appears to be an informal description rather than a precise specification capable to support automated integration. In general, while the phenomenon of semantic ....

S. Spaccapietra, C. Parent, and Y. Dupont. View integration: a step forward in solving structural conflicts. IEEE Transactions on KDE, 1992. This article was processed using the L a T E X macro package with LLNCS style

....structures and other tricks. The second strategy implies conceptualizing a larger number of (often similar, if not identical) views, and dropping useful hints from the physical structures. However, view integration is easier, since it corresponds to processes that are now standard 8 [B1] B3] [S1]. 7. DATA STRUCTURE CONCEPTUALIZATION The objective of this process is to discard technical constructs from the DMS compliant schema, to reduce DBMS dependent constructs, to eliminate performanceoriented data redundancies, to make hidden conceptual data structures explicit, and to produce a ....

Spaccapietra, S., Parent, C., View Integration : A Step Forward in Solving Structural Conflicts, Res. Report , EPFL, Lausanne (CH), IEEE Trans. on Knowledge and Data Engineering, October, 1992

....federated database systems (FDBS) integration is a function regularly performed at different levels and by different services depending on the organization of the FDBS environment. The value of the problem is well known, various approaches, techniques and sometimes tools were proposed (see, eg, [7, 22, 35, 36, 30, 29, 26] and surveys [2, 27] In spite of the diversity of approaches, several common points can be well identified. Integration consists of schema integration composing a global schema from the set of local ones, and data integration computing virtual extension of the global schema. Schema ....

....same data can be structured in different ways, and resolving such structural conflicts between representations is the key for correct integration. In fact, a methodology of integration is mainly determined by the treatment and the taxonomy of conflicts it adopts. Several approaches were proposed ([7, 19, 28, 30] and others) the most fundamental to date research is [29] where a taxonomy distinguishing semantic, descriptional, structural and heterogeneity conflicts was developed. It appears however that this is rather a substantial description of various situations leading to conflicts (and, indeed, it ....

S. Spaccapietra, C. Parent, and Y. Dupont. View integration: a step forward in solving structural conflicts. IEEE Transactions on KDE, 1992.

....Schema integration is a main component of conceptual design which is itself a part of the overall activity of database design. This explains the significant interest in schema integration methodologies: a vast diversity of various approaches, techniques and sometimes tools were proposed (see, eg, [10, 30, 42, 43, 40, 39, 36] and surveys [4, 37, 33] Moreover, to date the value of the issue has increased greatly due to the evident tendency of organizing modern (and of the nearest future) information systems on cooperative federal principals. Indeed, in the context of federated database systems (FDBS) integration is ....

....local schemas but not captured by any of them. All this constitutes a heuristic and hard to formalize nature of the subject and leads to an abundance of ad hoc solutions and methodologies (see also [31] A lot of approaches to classifying and managing structural conflicts were proposed ([10, 4, 25, 38, 40] and others) the most fundamental to date research is [39] where a taxonomy distinguishing semantic, descriptional, structural and heterogeneity conflicts was suggested. It appears however that this is rather an informal descrip 2 This phenomenon is often called semantic relativism. Moreover, a ....

S. Spaccapietra, C. Parent, and Y. Dupont. View integration: a step forward in solving structural conflicts. IEEE Transactions on KDE, 1992.

....outside the scope of the proposed techniques, and even structural conflicts within a sufficiently rich (in its collection of modeling constructs) data model is still a challenge. In particular, it appears that the taxonomy of conflicts between views proposed by Spaccapietra et al. (see, eg, SP91, SPD92b, SPD92a] where semantic, descriptional, structural and heterogeneity conflicts are distinguished, encompasses adequately the intuition and the diversity of approaches but says little about formal specification of conflicts. In contrast, in the paper we propose a formal graphical language for ....

....diagram markers from the local sketches. However, here diagram conflicts can arise, and these are real conflicts between views which can bring to light inconsistency of views 9 Thus, in respect to the taxonomy of conflicts and correspondence assertions proposed by Spaccapietra et al. [SP91, SPD92b, SPD92a] it can be said that owing to introducing additional interschema sketches into integration, AGO reduces all that conflicts to conflicts of two kinds structural conflicts (of being basic derived) and constraint conflicts (between diagram markers) while all kinds of correspondence ....

S. Spaccapietra, C. Parent, and Y. Dupont. View integration: a step forward in solving structural conflicts. IEEE Transactions on KDE, 1992.

.... heterogeneous attributes [9] Recent work on integrating object oriented schemas has analyzed the formal properties of integrated schemas with respect to information preservation [39] and extended the transformational expressiveness of rules to cope with more kinds of modeling differences [53, 52, 31, 9]. 2.2. Linguistic Analysis There exists a long research tradition in computer linguistics for the problem of extracting the meaning from free texts. Typical linguistic approaches rely on a syntactical and semantical analysis of the given text source. In the context of information extraction, the ....

Stefano Spaccapietra and Christine Parent. View integration: A step forward in solving structural conflicts. TKDE, 6(2):258--274 (1994).

....details provided in [LMR90, SL90] The work in database schema integration also addresses these issues and has a longstanding research history. Much of this work was surveyed in 1986 [BLN86] but continuing research has also led to many later results, for example, the results in [LNE89, BCW90, SP94] As the Web has become more prominent, a host of recent data extraction work has appeared, for example [AK97a, AK97b, Bri98, DEW97, EJN99, ECJ 99, HGMC 97, KWD97, MMK98, SL97, Sod97] and has been highlighted in many recent workshops, for example [CM99] Attacking the problem head on, ....

....we present. For (2) The semantic transformations we present focus on values, including value coercion, value decomposition and aggregation, object identifiers (OIDs) and generalizations and specializations of value sets. We also provide more traditional transformations similar to those found in [SP94] but in terms of OSM, which has a two component view of the world in terms of objects and relationships rather than the more popular three component view in terms of entities, relationships, and 3 attributes. Finally, for (3) the formalisms we present are complementary to the formalisms ....

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S. Spaccapietra and C. Parent. View integration: A step forward in solving structural conflicts. IEEE Transactions on Knowledge and Data Engineering, 6(2):258--274, April 1994.

....phase: ffl An n ary relationship r between n entities e 1 ; e n can be transformed into a new entity r with n binary relationships between r and e 1 ; e n . ffl A complex attribute a of an entity e which is an aggregation of n attributes s 1 ; s n , e.g. as used by [20], can be transformed into an entity a with n attributes s 1 ; s n and a relationship r between e and a. The domain of a is the Cartesian product of the domains of s 1 ; s n and this knowledge can subsequently be used in applying k b transformations. ffl A generalisation hierarchy ....

S. Spaccapietra and C. Parent. View integration: A step forward in solving structural conflicts. Technical report, Ecole Polytechnique Federale de Lausanne (1990).

....this architecture it is necessary to adopt a methodology that disciplines activities that accommodate the local schemas into a global one, and maps distributed and heterogeneous resources into global applications. The adoption of a conventional database integration methodology [3] 6] 17] [18] does not lead to a solution for GIS integration. They do not consider the graphic aspects for the representation of schemas nor the diversity and richness of semantic representation of the geographic data stored by the GIS. This work presents the MMultiGIS methodology to be incorporated into the ....

SPACCAPIETRA, S. & PARENT, C., 1994, "View integration: a step forward in solving structural conflicts", IEEE Transactions on Knowledge and Data Engineering, v.6, n. 2 (Apr.), pp. 240-274

....which consists of object databases, a global object schema created by integrating schemas of the component databases provides a uniform interface and high level location transparency for the users to retrieve data. A variety of approaches to schema integration have been proposed [1] 9] 15] [17]. In our previous work, we had presented a schema integration mechanism to achieve a global object schema for existing multiple object databases [13] Moreover, a form of equation was defined to denote the mapping between the global and component schemas in [14] One mechanism for processing the ....

S. Spaccapietra and C. Parent, View Integration: A Step Forward in Solving Structural Conflicts, IEEE Trans. on Knowledge and Data Eng., 6(2) (1994) pp.258-274. parameters description default setting for each global query Ndb number of component databases involved 3 N c number of global classes involved 1 4

....formalism for representing interscheme knowledge based on Description Logics is described, which forms the basis of our PDL formalism. However, 9] aims at representing interscheme knowledge while our aim is to extract new knowledge and to use PDL for formally representing extracted properties. [20] propose an automatic method for solving some semantic conflicts arising with scheme integration. In this respect, their aim is somehow similar to our own, even if with a more restricted scope. In any case, it is worth pointing out several important distinctions. First of all, 20] assumes that ....

....properties. 20] propose an automatic method for solving some semantic conflicts arising with scheme integration. In this respect, their aim is somehow similar to our own, even if with a more restricted scope. In any case, it is worth pointing out several important distinctions. First of all, [20] assumes that object terminological properties (e.g, entity synonymies) are preliminarly provided by the DBA for the presented methods to be applicable. Second, our approach comprises several aspects related to the design and the maintenance of cooperative information systems other than scheme ....

[Article contains additional citation context not shown here]

S. Spaccapietra, C. Parent , View Integration: A Step Forward in Solving Structural Conflicts, IEEE TKDE 6(2), 258-274, 1994.

....details provided in [LMR90, SL90] The work in database schema integration also addresses these issues and has a longstanding research history. Much of this work was surveyed in 1986 [BLN86] but continuing research has also led to many later results, for example, the results in [LNE89, BCW90, SP94] As the Web has become more prominent, a host of recent data extraction work has appeared, for example [DEW97, HGMC 97, MMK98] and has been highlighted in many recent workshops, for example [CM99] Attacking the problem head on, many researchers have o#ered their ideas on heterogeneity ....

....present. For (2) The semantic transformations we present focus on values, including value coercion, value decomposition and aggregation, object identifiers (OID s) and generalizations and specializations of value sets. We also provide more traditional transformations similar to those found in [SP94] but in terms of OSM, which has a two component view of the world in terms of objects and relationships rather than the more popular three component view in terms of entities, relationships, and attributes. Finally, for (3) the formalisms we present are complementary to the formalisms presented ....

[Article contains additional citation context not shown here]

S. Spaccapietra and C. Parent. View integration: A step forward in solving structural conflicts. IEEE Transactions on Knowledge and Data Engineering, 6(2):258--274, April 1994. 79

....overcome by transforming the local schemata into a canonical data model. In the second step schematic heterogeneity has to be overcome. In general, this step is a very complex task due to many kinds of conflicts. Therefore, different integration methodologies were proposed in [BLN86, NEL86, LNE89, SP94, SPD92, Bra93, TS93, Dup94, RPRG94, GCS95, PBE95] There are different requirements attributed to the integration of local schemata into an integrated schema (adopted from [BLN86] page 337) ffl Completeness and Correctness: The integrated schema must contain all concepts present in any ....

....are included in the second database as habitable buildings. Extensional Overlappings S1.Building: S1.Old Building: S2.Building: S2.Habitable Building: 1 2 3 4 5 Figure 2: Extensional Overlapping of Input Classes Most existing integration approaches [NEL86, LNE89, SPD92, Bra93, Dup94, SP94, RPRG94, GCS95, PBE95] do only mark pairs of classes with a possibly non empty population intersection as candidates for integration. Additionally, attributes may be marked to be corresponding. The resulting integration assertions can now be listed in the notation proposed by [SP94] ....

[Article contains additional citation context not shown here]

S. Spaccapietra and P. Parent. View Integration:A Step Forward in Solving Structural Conflicts. IEEE Transactions on Knowledge and Data Engineering, 6(2):258--274, April 1994.

....into a cohesive set. The integration process requires the identification of relationships and dependencies among data and procedures. A great number of methodologies, tools and solutions to integrate database schemas have been proposed and presented as survey in the literature as can be found in [5, 6, 20, 27, 30, 31, 39, 40, 62, 64, 77, 78, 80, 93, 101, 113]. Other solutions have been suggested by commercial and prototype systems suchas:DATAPLEX [14, 26, 104] DDTS [23, 91] DHIM [25] MERMAID [14, 91, 104] MULTIBASE [14, 23, 91, 97, 104] PEGASUS [1, 57] However, despite the methodologies, algorithms and heuristics that help the integration ....

S. Spaccapietra and C. Parent. View integration: A step forward in solving structural conflicts. IEEE Transactions on Knowledge and Data Engineering, 6(2):258-- 274, April 1994.

....schema is derived from the view definitions of the intended applications. On the other hand, in database integration in a distributed or federated database environment [SL90] schema integration aims at deriving an integrated schema which is a virtual view on all database classes to be integrated [Mot87, LNE89, SP94]. This integrated schema provides users a uniform and transparent interface to distributed and possibly heterogeneous databases. In modern database applications such as data warehousing [Wid95] schema integration is also a central issue. Since the early eighties, schema integration is discussed in ....

S. Spaccapietra and C. Parent. View Integration: A Step Forward in Solving Structural Conflicts. IEEE Transactions on Knowledge and Data Engineering, 6(2):258--274, April 1994. BIBLIOGRAPHY 27

....and procedural statement approaches. In the procedural statement approaches [Mot87, Koh93] integration operators must be provided and the DBA use these operators to specify what schema constructs correspond and how the schema constructs are integrated. In the declarative statement approaches [Red94, Spa94], the DBA need not to specify how to construct the integrated schema. Instead he provides correspondence statements for database constructs and the integrated schema can be obtained automatically or semi automatically. Our methodology for integrating the schema and extensional part of deductive ....

S. Spaccapietra and C. Parent, "View Integration: A Step Forward in Solving Structural Conflicts," IEEE Transactions on Knowledge and Data Engineering, Vol.6, No.2, April 1994.

....is illustrated in Figure 4(c) where in S 1 the knowledge that undergrad and postgrad are subsets of student allows us to move undergrad and postgrad to be subtypes of student in S 2 . 5. 3 N ary Relationships and Complex Attributes The first two equivalences in Figure 5 were proposed in [16, 17]. The third is a new equivalence we introduce, which removes the redundancy that occurs when schemas containing relationships of varying arity are merged. Entity complex attribute equivalence. This exists between two schemas S 1 and S 2 when S 1 contains a complex attribute a with sub attributes ....

S. Spaccapietra and C. Parent. View integration: A step forward in solving structural conflicts. Technical report, Ecole Polytechnique Federale de Lausanne, August 1990.

....resolve the so called structural conflicts between views when different DB users model the same information in different ways (see, for example, Fig. 1(a,b) again) A diversity of such conflicts was described in the literature, and a large body of research was devoted to their managing (see, eg, [39, 38] for a survey) but they still remain a stumbling block for the majority of view integration methodologies. It was however shown in [8, 10] that structural conflicts between views are nothing but a well known algebraic phenomenon when some basic items of one theory are derived items in another ....

S. Spaccapietra, C. Parent, and Y. Dupont. View integration: a step forward in solving structural conflicts. IEEE Transactions on KDE, 1992.

....polygon) Various conflits [11] can be detected during an integration of spatial databases. These conflicts can be grouped in two main categories: 1. Conflicts found in all classical heterogeneous databases integrations: conflicts of classification, of structure and of composition (fragmentation) [1, 13]. 2. Spatial conflicts which are proper to spatial databases: essentially metadata conflicts (data with different scales, without the same spatial referential, are of different geometrical types : Integration of classical databases has been widely studied [1, 13] Numerous techniques, ....

....composition (fragmentation) 1, 13] 2. Spatial conflicts which are proper to spatial databases: essentially metadata conflicts (data with different scales, without the same spatial referential, are of different geometrical types : Integration of classical databases has been widely studied [1, 13]. Numerous techniques, various methodologies and several prototypes propounded. To the best of our knowldege, no similar works concerning spatial databases exist. Globally, the process of classical database integration can be subdivided into three main phases. ffl The first preintegration stage ....

[Article contains additional citation context not shown here]

S. Spaccapietra and C. Parent. View integration: a step forward in solving structural conflict. IEEE Transactions on Knowledge and Data Engineering, Volume 6, Number 2, pages 258--274, 1994.

....of all the schemata to be integrated is assumed. Integrated data definition tools used in loosely coupled architectures are usually based on schema integration techniques employed in tightly coupled approaches [2,7,12,15] which in turn are often strongly similar to view integration techniques [20]. It is our opinion that traditional schema integration depends too heavily on conceptual modelling techniques aimed at the design of a new database. In the design phase, the focus is on defining abstract real world concepts to be represented by the classes of the new database. Different modelling ....

....Moreover, to ensure the integrity of the database, every database object in the extension of Employee is contained in the extension of Person as well. Thus Employee isa Person. Figure 1a illustrates this situation, where C=Person and C 0 =Employee. 2 2. 2 View integration View integration [20] is concerned with reconciling multiple conceptual models. That is, different user groups of a database to be developed will define entities of interest in the real world. Simplifying matters somewhat for the sake of presentation, we can state that these 1 Throughout this section, we will make ....

S. Spaccapietra & C. Parent, "View integration: A step forward in solving structural conflicts," IEEE Transactions on Knowledge and Data Engineering 6 (April 1994), 258--274.

....of schema integration has to deal with the design autonomy of the external databases. They use different data models (heterogeneity) model different aspects of the real world (do main perspective) and even the same situation may be represented in many different ways (semantic relativism) 6][26]. In this chapter we describe first the necessary framework for database integration, then we introduce a schema integration methodology based on augmentation rules [9] Finally we apply this methodology to an integration example showing how a graphical tool can support the principles of the ....

....(Update) Translation Decomposition Figure 6: Framework for Database Interoperability Two major categories of schema integration methodologies have been proposed until now. On the one hand exist strict integration methods which are using upward inheritance, correspondence assertions and rules [6][26] to achieve integration. They are sound, but at the same time intolerant and restrictive with respect to the real semantic modelled in the schemas which shall be integrated. On the other hand heuristic techniques using best paths, spanning trees and structural similarity [12] 13] 15] can handle ....

S. Spaccapietra, C. Parent, and Y. Dupont. View integration: a step forward in solving structural conflicts. In IEEE Transactions on Knowledge and Data Engineering. LBD, DI, EPF Lausanne 90, October 1992.

....by any means constitute all constraints. Significant work was done during the 1980s to systematise the approach, e.g. 2] 22] Later efforts have focussed on the at least partially automating the integration process, generally with ER or ER enhanced, although many of the ideas are generic [39] [40]. With the realisation of some that ER is not semantically strong enough, some have proposed logic models with the idea of translating to these, generally still from ER. However we propose that with the right (canonical) model it is possible to integrate schemas developed in a number of different ....

S. Spaccapietra and C. Parent. View integration: a step forward in solving structural conflicts. IEEE Transactions on Data and Knowledge Engineering, 1993.

....Multidatabase, Fuzzy relational database, Integration, Methodology, Fuzzy probabilistic model. 1 Introduction Multidatabase systems with global schemas have been a major research area in recent years [11, 16, 20] Among the issues, schema integration has probably received the most attention [3, 7, 8, 12, 21]. Many problems pertinent to schema integration such as name conflict, structural conflict, scale conflict, data inconsistency, etc. have been extensively studied. While some of these problems have been solved, some still remain to be solved. Parallel to the development in multidatabase systems, ....

S. Spaccapietra and C. Parent. View integration: A step forward in solving structural conflicts. IEEE Trans. on Knowledge and Data Engineering, April 1994.

....For a derivation rule of the form: A ( B, B and A are called the antecedent part and the consequent part of the rule, respectively. 3.2 Concept Mappings The second semantic conflict is concerned with the concept aspects, caused by the different perceptions of the same real world entities. [SP94, SPD92] proposed simple and uniform correspondence assertions for the declaration of semantic, descriptive, structural, naming and data correspondences and conflicts (see also [Du94] These assertions allow to declare how the schemas are related, but not to declare how to integrate them. Concretely, ....

....declaration of semantic, descriptive, structural, naming and data correspondences and conflicts (see also [Du94] These assertions allow to declare how the schemas are related, but not to declare how to integrate them. Concretely, four semantic correspondences between two concepts are defined in [SP94], based on their real Gamma world states (RWS) They are equivalence (j) inclusion ( or ) disjunction (OE) and intersection ( Equivalence between two concepts means that their extensions (populations) hold the same number of occurrences and that we should be able to relate those ....

[Article contains additional citation context not shown here]

S. Spaccapietra and P. Parent. "View integration: a step forward in solving structural conflicts ", IEEE Trans. on Knowledge and Data Engineering, vol. 6, No. 2, 258 - 274, April 1994.

....than by a query. 4.2 SCHEMA INTEGRATION We have presented a mechanism to unify (proxy) objects in different LOBs. We now concentrate on schema integration, that is to find out, what the common parts in the local schemas are, and to define a correspondence among them [ Civelek et al. 1989; Spaccapietra et al. 1992 ] We can consider Example 1, where Items, Parts, and Articles have a number function defined on it. Although they are named different, their semantics may be the same. Moreover, three functions with name weight are defined in the multiobjectbase. The weight of Items has the same semantics as ....

S. Spaccapietra, C. Parent, and Y. Dupont. View integration: A step forward in solving structural conflicts. IEEE Trans. on Knowledge and Data Engineering, October 1992.

....inheritance hierarchies are subhierarchies of the resulting merged hierarchy. Henceforth, the resulting hierarchy can become unnecessarily complex. We demonstrated that in [SS96b] Most of the proposed schema integration techniques including view integration techniques (e.g. MNE88, NEL86, SP94] are based on a data model similar to the ER model extended by subtype relationships. They take over the inheritance hierarchies from the local to the integrated schema level and adapt them to each other by adding new sub 2 or superclasses or deleting existing classes. In contrast to these ....

....schema evolution and tuning of object oriented schemata. The resulting schema can be influenced leading to schemata with specific properties while guaranteeing the correctness of the integrated schema. For the problem of view and schema integration there exist various approaches, e.g. GCS95, SP94, NG82] In contrast to these works we provide a simple formal method for integration producing minimal (number of classes) integrated schemata. These advantages results from applying the theory of formal concept analysis (cf. Wil92] to problems of integration of views and schemata, ....

S. Spaccapietra and P. Parent. View Integration: A Step Forward in Solving Structural Conflicts. IEEE Transactions on Knowledge and Data Engineering, 6(2):258--274, April 1994. BIBLIOGRAPHY 29

....integration is a function regularly performed at different levels and by different services depending on the organization of the FDBS environment. Significance of the problem is well known, various approaches, techniques and sometimes tools were proposed (see, eg, DH84, Mot87, WHW90, YAD 92, SPD92b, SPD92a, SST92] and surveys [BLN86, SL90] In spite of the diversity of approaches, several common points can be well identified. Integration consists of schema integration composing a global schema from the set of local ones, Supported by Grant 94.315 from the Latvian Council of Science ....

....in different ways, and resolving such structural conflicts between representations is the key for correct integration. In fact, a methodology of integration is mainly determined by the treatment and the taxonomy of conflicts it adopts. Several approaches were proposed ( DH84, LNE89, SP91, SPD92b] and others) the most fundamental to date research is [SPD92a] where a taxonomy distinguishing semantic, descriptional, structural and heterogeneity conflicts was proposed. It appears however that this is rather an informal description of various intuitions behind conflicts (and, indeed, it ....

S. Spaccapietra, C. Parent, and Y. Dupont. View integration: a step forward in solving structural conflicts. IEEE Transactions on KDE, 1992.

....database systems (FDBS) integration is a function regularly performed at different levels and by different services depending on the organization of the FDBS environment. Significance of the problem is well known, various approaches, techniques and sometimes tools were proposed (see, eg, [11, 21, 33, 34, 28, 27, 23] and surveys [4, 25] In spite of the diversity of approaches, several common points can be well identified. Integration consists of schema integration composing a global schema from the set of local ones, and data integration computing virtual extension of the global schema. In practice ....

....ways (the so called semantic relativism) and resolving such structural conflicts between representations is the key for correct integration. In fact, a methodology of integration is mainly determined by the treatment and the taxonomy of conflicts it adopts. Several approaches were proposed ([11, 20, 26, 28] and others) the most fundamental to date research is [27] where a taxonomy distinguishing semantic, descriptional, structural and heterogeneity conflicts was proposed. It appears however that this is rather an informal description of various intuitions behind conflicts (and, indeed, it properly ....

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S. Spaccapietra, C. Parent, and Y. Dupont. View integration: a step forward in solving structural conflicts. IEEE Transactions on KDE, 1992.

....We simply translate the function definitions of PDB 1 , PDB n into the database constructs of the so far integrated database and place the resulting definitions into the PDB. 4 Comparison With Related Work Since the 1980s a variety of approaches have been proposed for schema integration [Mot87, Koh93, Red94, Spa94]. Roughly these approaches can be divided into two categories: declarative statement and procedural statement approaches. Our methodology for integrating the schema and extensional part of deductive databases falls into the category of declarative statement approaches. Recently several papers ....

S. Spaccapietra and C. Parent, "View Integration: A Step Forward in Solving Structural Conflicts," IEEE Transactions on Knowledge and Data Engineering, Vol.6, No.2, April 1994.

....inverses of each other. It is not hard to verify that the union of library2 and library2 0 together with the above semantic relationship is equivalent to library3 of Section 2.2. Hence library3 can be taken as their integration. This schema transformation has been proposed in the literature [18]. 7.4 Schema Translation Given two schemas Gamma and Gamma 0 , a schema transformation oe: Gamma Gamma 0 is a translation from Gamma to Gamma 0 if Gamma j Gamma 0 . Schema translation between different data models is not any more difficult than that within the same data model, ....

S. Spaccapietra and C. Parent. View integration: A step forward in solving structural conflicts. IEEE Transactions on Knowledge and Data Engineering, 6(2):258--274, April 1994.

....(e.g. in one database, all the information may be contained in one relation, while in the other, the same information may be spread over two relations) They define a query language that takes such schematic mismatches into account when handling queries. In a similar vein, Spaccapietra and Parent [12] structural conflicts that arise when multiple databases contain similar, but structurally different data. They show how data across multiple databases can be linked or tied together based on common attribute values (even though the attribute names may be different across different databases) ....

S. Spaccapietra and C. Parent. (1994) View Integration: A Step Forward in Solving Structural Conflicts, IEEE Trans. on Knowledge and Data Engineering, 6, 2, pps 258--274.

....definitions. We simply translate the function definitions of PDB 1 ; PDBn into the database constructs of the so far integrated database and place the resulting definitions into the PDB. 4 Related Work Since the 1980s a variety of approaches have been proposed for schema integration [6, 5, 12, 18]. Roughly, these approaches can be divided into two categories: declarative statement and procedural statement approaches. Our methodology for integrating the schema and extensional part of deductive databases falls into the category of declarative statement approaches. Recently several papers ....

S. Spaccapietra and C. Parent, "View Integration: A Step Forward in Solving Structural Conflicts," IEEE Transactions on Knowledge and Data Engineering, Vol.6, No.2, April 1994.

....to an entity type from another schema, a relationship type compared to a relationship type, an attribute compared to an attribute. No mixed comparison (an attribute with an entity type, for instance) is supported. The consequence is poor interoperability and error prone techniques, as shown in [11]. With current methodologies, there is nothing which can be asserted between S5 and S6. An integration process instructed to merge S5 with S6 would produce a schema showing both entity types, just as they are. To avoid such an incorrect result, the DBA has to modify the input schemas before ....

S. Spaccapietra, C. Parent, Y. Dupont: "View integration: a step forward in solving structural conflicts", to appear in IEEE Transactions on Knowledge and Data Engineering , October 1992

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S. Spaccapietra and C. Parent. View Integration : A Step Forward in Solving Structural Conflicts. TKDE, 6(2):258--274, 1994.

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S. Spaccapietra and C. Parent. View Integration : A Step Forward in Solving Structural Conflicts. TKDE, 6(2):258--274, 1994.

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S. Spaccapietra and C. Parent, View integration: A step forward in solving structural con icts, IEEE Transactions on Knowledge and Data Engineering, 6(2):258-274, 1994.

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S. Spaccapietra and C. Parent. View integration: A step forward in solving structural conflicts. IEEE Transactions on Software and Data Engineering, 6(2):258--274, 1994.

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S. Spaccapietra and C. Parent. View Integration : A Step Forward in Solving Structural Conflicts. TKDE, 6(2):258--274, 1994.

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S. Spaccapietra and C. Parent. View Integration : A Step Forward in Solving Structural Conflicts. TKDE, 6(2):258--274, 1994. 29

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Spaccapietra, S., Parent, C., View Integration : A Step Forward in Solving Structural Conflicts, Res. Report , EPFL, Lausanne (CH), August

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Spacappietra, S., and C. Parent. " View Integration: A Step Forward in Solving Structural Conflicts," IEEE Transactions on Knowledge and Data Engineering, 6(2), 258-274, April 1994

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Spacappietra, S., and C. Parent. "View Integration: A Step Forward in Solving Structural Conflicts," IEEE Transactions on Knowledge and Data Engineering, 6(2), 258-274, April 1994

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SP94 S. Spaccapietra and P. Parent, "View integration: a step forward in solving structural conflicts", IEEE Trans. on Knowledge and Data Engineering, vol. 6, No. 2, 258 - 274, April 1994.

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