B. Cadish and Z. Diskin. Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations. In Next Generation of Information Technologies and Systems,NGITS'95, pages 69--79, 1995.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....modelling. Among this work Piessens has obtained results on the algorithmic determination of equivalences of model categories [27] which were intended to support plans for view integration. Meanwhile Diskin and Cadish have used sketches for a variety of modelling purposes including for example [14] and [15] They have been concentrating on developing the diagrammatic language of diagram operations . Others, including Lippe and ter Hofstede [25] Islam and Phoa [17] and Baklawski et al. [4] have been using category theory for data modelling. Recent work on updating problems has included ....

Zinovy Diskin and Boris Cadish. Algebraic graph-based approach to management of multidatabase systems. In Proceedings of The Second International Workshop on Next Generation Information Technologies and Systems (NGITS '95), 1995.

....AUSTRALIA email: mike mpce.mq. edu.au Abstract Category theoretic models of information systems have by now been widely used in industrial consultancies (for some examples see [6] and [3] and the models themselves have been developed in some detail in, for example, 4] 1] 10] 5] 11] [2] and [8] Although many information systems are never meant to be implemented computationally (for example paper based enterprise wide information models are frequently used by senior executives to help understand and plan the development of large corporations) the logic of an information system ....

B. Cadish and Z. Diskin, Algebraic graph based approach to management of multibase systems 1: Schema integration via sketches and equations, Next Generation of Information Technologies and Systems (NGITS'95), Naharia, Israel, (1995), 69--79.

....Permission to copy for private use granted. Theory and Applications of Categories, Vol. 1, No. 8 157 a first interesting result: the existence of so called canonical forms for a large subset of data specifications. Other categorical formalisations of semantic data specifications exist. 9] and [11] propose generalized sketches in the sense of [12] as a formalisation for dataspecifications. In [15] object oriented data specification systems based on categorical constructs are defined, and a query language based on universal constructions is shown to be at least as expressive as relational ....

Z. Diskin, B. Cadish, I.Beylin. "Algebraic graph-based approach to management of multibase systems, II: Algebraic aspects of schema integration." To appear in the proceedings of the Moscow ACM Chapter Conference ADBIS'95, Moscow, Russia, June 1995.

....1995. Permission to copy for private use granted. Theory and Applications of Categories, Vol. 1, No. 8 157 a first interesting result: the existence of so called canonical forms for a large subset of data specifications. Other categorical formalisations of semantic data specifications exist. [9] and [11] propose generalized sketches in the sense of [12] as a formalisation for dataspecifications. In [15] object oriented data specification systems based on categorical constructs are defined, and a query language based on universal constructions is shown to be at least as expressive as ....

B. Cadish, Z. Diskin. "Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations." To appear in the proceedings of Next Generation of Information Technologies and Systems, NGITS'95, Naharia, Israel, June 1995.

....by sketches so that integration of n views is reduced to integration of (n 1) sketches S 1 ; Sn ; SCI (where CI stands for correspondence information) The second key idea consists in specifying structural conflicts via equations between algebraic terms. To wit, we show (see also [5, 2]) that all the diversity example, in the ER data model the same object of the real world can be presented as an entity, or as an attribute, or as a relationship. 3 We assert that none of the conventional graphical models has this property 4 Any formal specification can be expressed in the ....

....procedure the steps which can be fully automated and those that need human assistance. In its turn, the latter can be also made computer aided and, speaking in general, the sketch framework brings to light limitations and possibilities of automation in schema and data integration(see also [2]) On the other People = Person Correspondence information sketch, SCI SCI:People = S1:People, SCI:Person = S2:Person Correspondence equations, ECI Fig. 6. Another example of specifying correspondence information hand, our experience has shown that sketches turn out to be very handy as a ....

B. Cadish and Z. Diskin. Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations. In Next Generation of InfoTechnologies and Systems, NGITS'95, 2nd Int.Workshop (Israel), 1995.

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Z. Diskin, B. Cadish, and I. Beylin. Algebraic graph-based approach to management of multibase systems, II: Mathematical aspects of schema integration. To appear in Proc.of the Moscow ACM Chapter 2nd Int.Conf. "Advances in DataBases and Information Systems, ADBIS'95" (Moscow,Russia) June 1995.

.... is just a way of expressing the ordinary definition of instance, however, it makes possible to develop a data model independent framework in a concise way, in particular, to define precisely what semantic overlapping of views does mean, and how it can be specified in schema integration ([5, 11]) So, we will assume that among objects of Schema there is a subcollection Sem of schemas regarded as semantic so that a database instance over S is defined to be an arrow e : S W for some W 2 Sem. Further, as soon as a schema W belongs to Sem, its items should be thought of as collections of ....

Z. Diskin. Algebraic graph-based approach to management of multibase systems, II: Algebraic aspects of schema integration. Technical Report 07, Frame Inform Systems/LDBD, Riga, Latvia, 1994.

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Z. Diskin. Algebraic graph-based approach to management of multibase systems. Part 1: View integration via sketches and equations. Technical report, Frame Inform Systems, Riga, 1994.

....flexible framework where the signature of diagram properties is arbitrary and userdefined. Actually, this leads to a metalogical framework where various kinds of sketches can be defined: a suitable for this goal concept of generalized sketch was proposed by Makkai in [31] and, independently, in [13, 18] (in [18] the concept is further developed by enriching the construction with dynamic constraints which seem novel for the sketch framework) Furthermore, as soon as some specification language is proposed, it should be endowed with an appropriate deduction machinery, that is, with a mechanism of ....

....ways because inputs and outputs of such operations are complex data structures (specified by sketches) So, it is crucial for the approach to find a proper construction of composing diagram operations, or, in other words, of a term freely composed from diagram operations. The solution proposed in [13] is similar to that one utilized in ordinary algebra where a derived operation is specified by a tree. Namely, there was proposed a construction of tree labeled by diagram operations in a special way providing coherence between inputs outputs of composed operations, and a basic theorem of sketch ....

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Z. Diskin. Algebraic graph-based approach to management of multibase systems, II: Mathematical aspects of schema integration. Technical Report 95-02, Frame Inform Systems/LDBD, Riga,Latvia, 1995. (On ftp: //ftp.cs.chalmers.se/pub/users/diskin/tr9502.*).

....once more its suitability for any data model. On the other hand, sketches are important themselves since they form a powerful specification paradigm capable to emulate any formalizable data model. Actually, we believe that sketches can be very useful in practice of data modeling. In papers [7, 8, 5] we have demonstrated the suitability of our framework for managing schema integration. The focus of the present paper is on specifying views and refinements. In particular, we show that the schema grid introduced in [3] is a very special case of the much more general construction of metasketch ....

.... justification for the conjecture can be seen in the successful usage of the arrow framework in approaching the extremely difficult task of heterogeneous database integration ( 18, 17] One more example is the arrow approach to resolving structural conflicts in schema integration we described in [7, 8]. We summarize the considerations in the slogan: the logic of complex information system design is the arrow logic. ....

B. Cadish and Z. Diskin. Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations. In Next Generation of Information Technologies and Systems, NGITS'95, 2nd Int.Workshop, pages 69--79, Naharia (Israel), 1995.

.... E i to the corresponding entity sets E i ; i = 1; n; in addition, the family (f i ; i = 1; n) must satisfy a certain property to guarantee that elements of R can be indeed identified with tuples of references (in the context of semantic modeling the construction was described in [7, 26, 12] and probably in other works, see also section 2.1 below) The figure just described is an arrow diagram, 3 it is a branch of modern algebra where graph based algebra and logic are studied; a standard reference suitable for computer science is [4] the property we have mentioned is a diagram ....

....theory into the field of conceptual modeling. In particular, schema transformation is reduced to a graph based counterpart of algebraic term rewriting the so called diagram chasing (a small example of the procedure is shown in section A. 3) Effectiveness of the approach was demonstrated in [7, 8] where an algebraic sketch based methodology for heterogeneous view integration is developed. By suggesting sketches we do not wish to force all practitioners and researchers to use the same universal graphical language let everyone use that collection of graphical constructs one likes. What we ....

B. Cadish and Z. Diskin. Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations. In Next Generation of Information Technologies and Systems, NGITS'95, 2nd Int.Workshop, pages 69--79, Naharia (Israel), 1995.

....machinery, and the success hardly can be achieved with ad hoc approaches built from scratch. This explains the far from ideal situation in the modern SM and, on the other hand, suggests that CT should possess a great potential for software engineering applications. Indeed, it was demonstrated in [13, 29, 8, 10, 19] that even initial categorical arrangement of standard specification languages used in SM leads to practically useful results. This success is remarkable and supports the claim. It would be however too optimistic to hope that CT in its current state is immediately applicable for systematic using ....

....specifying constraints on data and so, in general, operations (queries) may be involved in data definition schemas as such. Moreover, for complex universes whose schema appears as the result of integrating local view schemas, the presence of queries in data schemas is a rule rather than exception ([8, 10]) In this context, the discussion below is motivated by the problem of specifying queries and query languages rather than their computational complexity and expressive power. 1.3.1 The relevance of algebraic framework for DB theory is well known and goes back to the classical Codd s papers (see ....

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B. Cadish and Z. Diskin. Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations. In Next Generation of Information Technologies and Systems, NGITS'95, 2nd Int.Workshop, pages 69--79, Naharia (Israel), 1995. (On ftp: //ftp.cs.chalmers.se /pub/users/diskin/ PAPERS-DB/ngits95.ps.gz).

.... [DS=complex,PS=simple] were developed and utilized in [12, 13] These latter papers aim at technology development rather than purely computer science research, in particular, the sketch based solution of the long standing problem of heterogeneous view integration was found (it is described in [5, 6]) Modeling transactions (the square [complex,complex] is in the stage of initial development if to speak about technology. Metadata modeling (interpretation 7, the plane PS=0) was developed in [15, 9] and in [10] an integral data model independent framework for specifying database architecture ....

B. Cadish and Z. Diskin. Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations. In Next Generation of Information Technologies and Systems, NGITS'95, 2nd Int.Workshop, pages 69--79, Naharia (Israel), 1995. (On ftp: //ftp.cs.chalmers.se /pub/users/diskin/ PAPERS-DB/ngits95.ps.gz).

....data about correspondence between component schemas. Federal superview schemas S I a ; S I b are obtained by integration of component schemas with the correspondence information schemas (an automated procedure of sketch integration in the presence of inter schema conflicts was proposed in [6, 8]) The arcs hung on arrows coming into S I a ; S I b denote the cover constraint (Table 1) They show that each item of the integrated schema can be found in either one of the component schemas or in the correspondence schema. In the explanation column on the right of Fig. 7, data model means ....

B. Cadish and Z. Diskin. Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations. In Next Generation of Information Technologies and Systems, NGITS'95, 2nd Int.Workshop, pages 69--79, Naharia (Israel), 1995.

....Foreword. Category theory is well known as a high level polymorphic framework suitable for specifying complex structures and formalisms. Quite unexpectedly, however, it turned out that even elementary category theory notions can be valuable in practice of software engineering (see [JD93, DDJ93, CD95, CD96] and in the summer of 1994 we wrote a manifesto ( CD94] the first version of the present one a ) to claim our belief in the extreme fruitfulness of incorporating the category theory (CT) machinery into the database (DB) area. That time we did not know about works by Johnson with ....

.... of our previous predictions: the list of (CT DB) publications is actually growing (though not so rapidly as we hoped) and at a recent International Workshop ( BKZ95] there was a special section on (CT DB) and it seems that methodologies being developed in Sydney ( JD93, DDJ93] and Riga ( CD95, CD96] meet some (methodological, of course, but partly also technological) challenges in the DB area. As before, we forecast an intensive growth of CT and DB interaction and present below the third version of our manifesto in which the text is slightly revised and the bibliography list is ....

[Article contains additional citation context not shown here]

B. Cadish and Z. Diskin. Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations. In Next Generation of Information Technologies and Systems, NGITS'95, 2nd Int.Workshop, pages 69--79, Naharia (Israel), 1995.

.... with operation markers) can be converted into a parsing tree showing the process of stepwise augmenting the initial sketch via applying diagram operations from the Table 1 (or from another signature) A methodology of parsing sketch with operation markers was proposed in [16] and developed in [13] (see Appendix A below) The sketch parsing is much more intricate than the standard algebraic term parsing since inputs and outputs of diagram operations are complex structures which can be connected in a variety of ways. Such a sketch is correct if, roughly speaking, for each derived node arrow ....

Z. Diskin. Algebraic graph-based approach to management of multibase systems, II: Mathematical aspects of schema integration. Technical Report 9502, Frame Inform Systems/LDBD, Riga,Latvia, 1995. (On ftp: //ftp.cs.chalmers.se/pub/users/diskin/tr9502.*).

No context found.

B. Cadish and Z. Diskin. Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations. In Next Generation of Information Technologies and Systems, NGITS'95, 2nd Int.Workshop, pages 69-- 79, Naharia (Israel), 1995.

....has two sides: extensional (data modeling) and intensional (metadata modeling) As for the former, it is the task of developing graph based logics supporting semantic specification languages like various ER diagrams, semantic networks etc. Here the concept of generalized sketch introduced in [9, 6, 7], see also [5, 11, 6] provides a solution, and even the initial steps have led to information modeling methodologies of real practical value ( 11, 4, 2, 3] On the intensional level, the goal is to offer a graphical yet precise formal language for reasoning about such things as, say, a system of ....

....extensional (data modeling) and intensional (metadata modeling) As for the former, it is the task of developing graph based logics supporting semantic specification languages like various ER diagrams, semantic networks etc. Here the concept of generalized sketch introduced in [9, 6, 7] see also [5, 11, 6], provides a solution, and even the initial steps have led to information modeling methodologies of real practical value ( 11, 4, 2, 3] On the intensional level, the goal is to offer a graphical yet precise formal language for reasoning about such things as, say, a system of views over a ....

[Article contains additional citation context not shown here]

Z. Diskin. Algebraic graph-based approach to management of multibase systems, II: Mathematical aspects of schema integration. Technical Report 9502, Frame Inform Systems/LDBD, Riga,Latvia, 1995. (On ftp: //ftp.cs.chalmers.se/pub/users/diskin/tr9502.*).

....supporting semantic specification languages like various ER diagrams, semantic networks etc. Here the concept of generalized sketch introduced in [9, 6, 7] see also [5, 11, 6] provides a solution, and even the initial steps have led to information modeling methodologies of real practical value ([11, 4, 2, 3]) On the intensional level, the goal is to offer a graphical yet precise formal language for reasoning about such things as, say, a system of views over a database (DB) schema, or a system of DBs connected into a federal environment, or a system of different query languages in the same ....

B. Cadish and Z. Diskin. Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations. In Next Generation of Information Technologies and Systems, NGITS'95, 2nd Int.Workshop, pages 69--79, Naharia (Israel), 1995.

....counterpart of the familiar problem (in relational data models) of whether two dependencies are consistent. The latter is known to be undecidable, that implies undecidability of the view consistency problem in general. However it can be decidable in some special but interesting cases. See [9] for some details. Thus, in respect to the taxonomy of conflicts and correspondence assertions proposed by Spaccapietra et al. [17, 19, 18] it can be said that owing to introducing additional inter schema sketches into integration, AGO reduces all that conflicts to conflicts of two ....

Z. Diskin, B. Cadish, and I. Beylin. Algebraic graph-based approach to management of multibase systems, II: Mathematical aspects of schema integration. Technical Report 9502, Frame Inform Systems/LDBD, Riga,Latvia, 1995. On ftp: //ftp.cs.chalmers.se/pub/users/diskin/tr9502.*

....nature of all its constructs and procedures. This paper outlines the main concepts of our approach relevant to integration of schemas. Reader should consult [8, 6, 7] for more detail and examples. Problems of data integration (that is, computing queries on the virtual schema) are touched upon in [5]. Sketches. The core of AGO is a family of graph based specification languages in which specifications are directed multigraphs endowed with a labeling formalism of a special kind. Certainly, conventional semantic schemas are also graphs endowed with special labeling, however, the question is ....

B. Cadish and Z. Diskin. Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations. In Next Generation of Information Technologies and Systems, NGITS'95, pages 69--79, Naharia (Israel), 1995. Extended abstract is available on ftp: //ftp.cs.chalmers.se/pub/users/diskin/ngits95.*

.... such a strange thing are already developed in the mathematical category theory (which was entitled by abstract nonsense during its early days) So, there emerges an important task of categorial formulating the DB theory conceptual framework, and initial steps were made mutually independently in [17, 18, 19, 30, 29, 16, 6], see also an explicit statement of the problem in [8] and a survey [26] 4 3 Italic is ours 4 A similar problem in the semantics of programming languages was resolved with introducing the concept of institution by Goguen and Burstall ( 14] see also an illuminating discussion by Meseguer in ....

....data about correspondence between component schemas. Federal superview schemas S I a ; S I b are obtained by integration of component schemas with the correspondence information schemas (an automated procedure of sketch integration in the presence of inter schema conflicts was proposed in [6, 7]) The arcs hung on arrows coming into S I a ; S I b denote the cover constraint (Table 1) They show that each item of the integrated schema can be found in either one of the component schemas or in the correspondence schema. In the explanation column on the right of Fig. 4, data model means ....

[Article contains additional citation context not shown here]

B. Cadish and Z. Diskin. Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations. In Next Generation of Information Technologies and Systems, NGITS'95, 2nd Int.Workshop, pages 69--79, Naharia (Israel), 1995.

....is that it is provably ( universal: it follows from some general results of categorical logic that any formal data specification can be replaced by a semantically equivalent sketch. This provides a real possibility of handling semantic models heterogeneity via SkeDM. Moreover, as it was shown in [3], the sketch language makes it possible to develop a practically effective approach to automated heterogeneuos view integration built upon formal algebraic manipulations with sketches. Application of the approach to conceptual modeling is also discussed in [6] Another advantage of the ....

B. Cadish and Z. Diskin. Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations. In Next Generation of Information Technologies and Systems,NGITS'95, 2nd Int.Workshop, pages 69-- 79, Naharia (Israel), 1995.

No context found.

B. Cadish and Z. Diskin. Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations. In Next Generation of Information Technologies and Systems,NGITS'95, pages 69--79, 1995.

No context found.

B. Cadish and Z. Diskin. Algebraic graph-based approach to management of multibase systems, I: Schema integration via sketches and equations. In Next Generation of Information Technologies and Systems, NGITS'95, pages 69--79, 1995.

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