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ILOG: Declarative Creation and Manipulation of Object Identifiers
, 1991
"... yosikawaQkyotosu.ac.jp Abstract: This paper introduces ILOG ( a declarative language in the style of (stratified) datalog ( which can be used for querying, schema translation, and schema augmentation in the context of objectbased data models. The semantics of ILOG is based on the use of Skolem fun ..."
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Cited by 106 (1 self)
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yosikawaQkyotosu.ac.jp Abstract: This paper introduces ILOG ( a declarative language in the style of (stratified) datalog ( which can be used for querying, schema translation, and schema augmentation in the context of objectbased data models. The semantics of ILOG is based on the use of Skolem functors, and is closely related to semantics for objectbased data manipulation languages which provide mechanisms for explicit creation of object identifiers (OIDs). A normal form is presented for ILOG ’ programs not involving recursion through OID creation, which identifies a precise correspondence between OIDs created in the target, and values and OIDs in the source. The expressive power of various sublanguages of ILOG ’ is shown to range from a natural generalization of the conjunctive queries to the objectbased context, to a language which can specify all computable database translat.ions (up to duplicate copies). The issue of testing vuliilityof ILOG programs translat.ing one semantic schema to another is studied: cases are presented for which severalvalidity issues (e.g., functional and/or subset relationships in the
Finitely Representable Databases
, 1995
"... : We study classes of infinite but finitely representable databases based on constraints, motivated by new database applications such as geographical databases. We formally define these notions and introduce the concept of query which generalizes queries over classical relational databases. We prove ..."
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Cited by 57 (8 self)
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: We study classes of infinite but finitely representable databases based on constraints, motivated by new database applications such as geographical databases. We formally define these notions and introduce the concept of query which generalizes queries over classical relational databases. We prove that in this context the basic properties of queries (satisfiability, containment, equivalence, etc.) are nonrecursive. We investigate the theory of finitely representable models and prove that it differs strongly from both classical model theory and finite model theory. In particular, we show that most of the well known theorems of either one fail (compactness, completeness, locality, 0/1 laws, etc.). An immediate consequence is the lack of tools to consider the definability of queries in the relational calculus over finitely representable databases. We illustrate this very challenging problem through some classical examples. We then mainly concentrate on dense order databases, and exhibit...
Management of Multiple Models in an Extensible Database Design Tool
 In Proceedings of EDBT’96, LNCS 1057
, 1996
"... . We describe the development of a tool, called MDM, for the management of multiple models and the translation of database schemes. This tool can be at the basis of an integrated CASE environment, supporting the analysis and design of information systems, that allows different representations for th ..."
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Cited by 48 (12 self)
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. We describe the development of a tool, called MDM, for the management of multiple models and the translation of database schemes. This tool can be at the basis of an integrated CASE environment, supporting the analysis and design of information systems, that allows different representations for the same data schemes. We first present a graphtheoretic framework that allows us to formally investigate desirable properties of schema translations. The formalism is based on a classification of the constructs used in the known data model into a limited set of types. Then, on the basis of formal results, we develop general methodologies for deriving "good" translations between schemes and, more in general, between models. Finally, we define the architecture and the functionalities of a first prototype that implements the various features of the approach. 1 Introduction During the past decade, the availability and use of automated tools for the analysis and development of information systems...
On the expressive power of database queries with intermediate types
 Journal of Computer and System Sciences
, 1991
"... The setheight of a complex object type is defined to be its level of nesting of the set construct. In a query of the complex object calculus which maps a database D to an output type T,anintermediate type is a type which is used by some variable of the query, but which is not present in D or T.Fore ..."
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Cited by 47 (2 self)
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The setheight of a complex object type is defined to be its level of nesting of the set construct. In a query of the complex object calculus which maps a database D to an output type T,anintermediate type is a type which is used by some variable of the query, but which is not present in D or T.Foreachk, i ≥ 0 we define CALCk,i to be the family of calculus queries mapping from and to types with setheight ≤ k and using intermediate types with setheight ≤ i. In particular, CALC0,0 is the classical relational calculus, and CALC0,1 is equivalent to the family of secondorder (relational) queries. Several results concerning these families of languages are obtained. A primary focus is on the families CALC0,i, which map relations to relations. Upper and lower bounds in terms of hyperexponential time and space on the complexity of these families are provided. The CALC0,i hierarchy does not collapse with respect to expressive power. The union ∪0≤iCALC0,i is exactly the family of elementary queries, i.e., queries with hyperexponential complexity. The expressive power of queries from the complex object calculus interpreted using semantics based on the use of arbitrarily large finite or infinite set of invented values is studied. Under these semantics, the expressive power of the relational calculus is not increased, and the CALC0,i hierarchy collapses at CALC0,1. In general, queries with these semantics may not be computable. We also consider an alternative semantics which yields a family of queries equivalent to the computable queries. 1
Modelindependent schema and data translation
 In EDBT, volume 3896 of LNCS
, 2006
"... Abstract. We describe MIDST, an implementation of the model management operator ModelGen, which translates schemas from one model to another, for example from OO to SQL or from SQL to XSD. It extends past approaches by translating database instances, not just their schemas. The operator can be used ..."
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Cited by 33 (7 self)
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Abstract. We describe MIDST, an implementation of the model management operator ModelGen, which translates schemas from one model to another, for example from OO to SQL or from SQL to XSD. It extends past approaches by translating database instances, not just their schemas. The operator can be used to generate database wrappers (e.g. OO or XML to relational), default user interfaces (e.g. relational to forms), or default database schemas from other representations. The approach translates both schemas and data: given a source instance I of a schema S expressed in a source model, and a target model TM, it generates a schema S ′ expressed in TM that is “equivalent ” to S and an instance I ′ of S ′ “equivalent ” to I. A wide family of models is handled by using a metamodel in which models can be succinctly and precisely described. The approach expresses the translation as Datalog rules and exposes the source and target of the translation in a generic relational dictionary. This makes the translation transparent, easy to customize and modelindependent. 1
Domain Independence and the Relational Calculus
 Acta Informatica
, 1993
"... Several alternative semantics (or interpretations) of the relational (domain) calculus are studied here. It is shown that they all have the same expressive power, i.e., the selection of any of the semantics neither gains nor loses expressive power. Since the domain is potentially infinite, the answe ..."
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Cited by 24 (7 self)
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Several alternative semantics (or interpretations) of the relational (domain) calculus are studied here. It is shown that they all have the same expressive power, i.e., the selection of any of the semantics neither gains nor loses expressive power. Since the domain is potentially infinite, the answer to a relational calculus query is sometimes infinite (and hence not a relation). The following approaches which guarantee the finiteness of answers to queries are studied here: outputrestricted unlimited interpretation, domain independent queries, outputrestricted finite and countable invention, and limited interpretation. Of particular interest is the outputrestricted unlimited interpretation  although the output is restricted to the active domain of the input and query, the quantified variables range over the infinite underlying domain. While this is close to the intuitive interpretation given to calculus formulas, the naive approach to evaluating queries under this semantics calls ...
Schema Translation between Heterogeneous Data Models in a Lattice Framework
 In Sixth IFIP TC2 Working Conference on Data Semantics (DS6
, 1995
"... In this paper we study the problem of translating schemes between different data models, in a formal framework that refers to a wide range of models. We first introduce a graphtheoretic formalism that allows us to uniformly represent schemes and models, to compare different data models and to descri ..."
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Cited by 18 (2 self)
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In this paper we study the problem of translating schemes between different data models, in a formal framework that refers to a wide range of models. We first introduce a graphtheoretic formalism that allows us to uniformly represent schemes and models, to compare different data models and to describe the behavior of basic translations. The formalism is based on a classification of the constructs used in the known data model into a limited set of types. Then, we study in this framework formal properties of scheme translation between heterogeneous data models, and we develop a method for deriving translations that enjoy those properties. Keywords Data models, Metamodel, Heterogeneity, Schema translation, Lattice structure. 1 INTRODUCTION 1.1 Motivations and background It is widely accepted now that a conceptual data model be used in the analysis phase and many tools exist that support the analysis and design of information systems (see for instance the book of Batini et al. (1992))...
MDM: a MultipleDataModel Tool for the Management of Heterogeneous Database Schemes
"... MDM is a tool that enables the users to define schemes of different data models and to perform translations of schemes from one model to another. These functionalities can be at the basis of a customizable and integrated CASE environment supporting the analysis and design of information systems. MDM ..."
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Cited by 16 (4 self)
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MDM is a tool that enables the users to define schemes of different data models and to perform translations of schemes from one model to another. These functionalities can be at the basis of a customizable and integrated CASE environment supporting the analysis and design of information systems. MDM has two main components: the Model Manager and the Schema Manager. The Model Manager supports a specialized user, the model engineer, in the definition of a variety of models, on the basis of a limited set of metaconstructs covering almost all known conceptual models. The Schema Manager allows designers to create and modify schemes over the defined models, and to generate at each time a translation of a scheme into any of the data models currently available. Translations between models are automatically derived, at definition time, by combining a predefined set of elementary transformations, which implement the standard translations between simple combinations of constructs.
On bulk data type constructors and manipulation primitives  a framework for analyzing expressive power and complexity
 Proceedings of 2nd International Workshop on Database Programming Languages
, 1989
"... We present a framework for analyzing the complexity and expressive power of many existing languages for manipulating information in bulk data types. The framework is based on four dimensions: the \cardinality measure " of the underlying data model � procedural vs. declarative� the presence ..."
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Cited by 1 (0 self)
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We present a framework for analyzing the complexity and expressive power of many existing languages for manipulating information in bulk data types. The framework is based on four dimensions: the \cardinality measure &quot; of the underlying data model � procedural vs. declarative� the presence of iteration � and the presence of \invention&quot;. Several languages from the literature which correspond to various combinations of these dimensions are categorized into ve families of queries, ranging from QLOGSPACE to a family which is more expressive than the computable queries. 1