C. Beeri. Formal Models for object oriented databases. In Proc. 1st Intl. Conf. on Deductive and object-oriented databases, pages 370--396, 1989.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....IMPORT PROPERTY x:email, x:supervises 6 Classification and Consistency 6. 1 Automatic hierarchy classification As users can combine arbitrary algebraic operations in the view , the semantic characterization of the view cannot be given automatically because this problem is undecidable [Run92,Bee89] We therefore introduced additional possibilities to conveniently define views on classes where the classification can automatically be determined from query semantics (cf. section 5.1) Figure 7 provides an overview of the classification which is semantically correct for each algebraic ....

C. Beeri. Formal Models for object oriented databases. In Proc. 1st Intl. Conf. on Deductive and object-oriented databases, pages 370--396, 1989.

....model [16, 17] In this paper, we deal with the introduction of temporal schema versioning in an object oriented database, also taking into account formal aspects. Within the object oriented framework, theoretical work has been done in the field of programming languages [18, 19] and databases [20, 21, 22], also including temporal ones [11] whereas thorough studies concerning schema versioning are still lacking. To this purpose, we will define (Object Oriented Data Model contextualized to chema ersions) that is a formal model for the management of temporal schema versioning in ....

C. Beeri, Formal Models for Object Oriented Databases, in: Proc. of the 1st Int. Conf. on Deductive and Object-Oriented Databases (DOOD), Kyoto, Japan, 1989, pp. 370--395.

.... includes multi valued attributes, which we call a multi valued path expression, its semantic consequences require more than just the nesting of objects[22] Specifically,themulti valued path expression allows for modeling of the quantification over nested sets called restricted quantification[4, 5, 27] and handling of recursion, which necessitates an explicit specification of its semantics[17] Analogously, a visual approach to object oriented query languages should facilitate the corresponding construct with the explicit semantics of a multi valued path expression. Now, in order to visually ....

....edge represents the notion of variable binding and the functionality of an attribute while a flattening edge corresponds to the functionalityofdot functions of a path expression at the nesting[22] levels of more than one. The latter type of edge explicitly represents the notion of flatten ing[4, 20] the values resulted from the function application to preserve the first orderness[3, 4, 19] These primitives, combined together, visually simulate the inter object relationships implied in path expressions and integrates the notion of object identity stemming from the inherent semantics of the ....

[Article contains additional citation context not shown here]

Beeri, C., "Formal Models for Object-Oriented Databases," In Proc. of the 1st Intl. Conf. on Deductive and Object-Oriented Databases, pages 370--395, Kyoto, Dec. 1989.

....for a procedural hypergraph query and update language. Keywords. object oriented data model, value oriented data model, complex object, object schema, hypergraph, functional dependencies, class, multi level abstraction, inheritance, sharing. 1. Introduction Object oriented data models [4, 5, 6, 7, 17, 27] attempt to overcome some of the deficiencies of value oriented data models [9, 16, 25] The predominant value oriented data model has been the relational model [9] which is limited to flat relational structures. Nested relations [19, 21, 26] extend the applicability of the relational model by ....

....identity is independent of attribute values and is achieved by equipping each database object with a unique identifier. Several advantages accrue with attribute independent identity : arbitrarily complex objects can be represented, objects can share common sub objects, and updates are simplified [4, 7, 11]. As well as attribute independent ################ Appeared in Data Knowledge Engineering, Vol. 6, No. 3, pp. 205 224, 1991. 2 object identity, it is generally accepted that object oriented data models should provide mechanisms for inheritance between classes of objects and for the ....

[Article contains additional citation context not shown here]

BEERI C. 1989. Formal models for object oriented databases. Proceedings of International Conference on Deductive and Object-Oriented Databases, pp. 370-395.

....of a database schema as typed variables in some update language. We call such a variable a state variable and the collection of these state variables a state space. For a relational database schema each relation schema gives rise to a state variable. For object oriented database schemata [1, 2, 6, 11, 13] the state variables would correspond to the classes. The types that are allowed depend on the datamodel. Then a static constraint is simple a rst order formula I with (some of) the state variables occurring freely in I. Therefore, a many sorted (because of the types) rst order logic L is ....

C. Beeri, Formal Models for Object-Oriented Databases, Proc. 1st DOOD (1989), 370-395.

....each function is also checked recursively (the third case) Notice that the lose operation and the deletion of objects have a strong impact on constructed values. Without objects, instances of constructed types such as sets and functions are regarded as values that can not be created or deleted [6]. However, if object types are used to construct sets of functions, the constructed domains become dynamic as well, since the existence of constructed values depends on the active domains of object types. Example: Assume the variable declarations p : Pers; e : Empl; mgr : Mngr; jones pers ....

C. Beeri. Formal models for object-oriented databases. In W. Kim, J.- M. Nicolas, and S. Nishio, editors, Proc. 1st Int'l Conf. on Deductive and Object-Oriented Databases, pages 370--395, Kyoto, December 1989. NorthHolland. Revised version appeared in "Data & Knowledge Engineering", Vol. 5, North-Holland.

....of theoretical research is being carried on in the area of non temporal object oriented programming 1 1 1 T T T (i) ii) iii) 1.1 Related works Objects can migrate during their lifetime from one class to another. languages and databases and theoretical foundations are being established [1, 3, 14]. In particular, issues concerning type systems and type checking have been widely investigated in a non temporal object oriented framework [2, 5] These issues, however, have never been addressed in the framework of temporal object oriented data models. Thus, the extension of established ....

....of time supported) how these characteristics are integrated, that is, how time is associated with objects. For the object oriented characteristics, we consider in the table only two dimensions: whether values are distinguished from objects (and types from classes at the intensional level) [3, 14], and whether class features are supported. As a general remark, we point out that most proposed approaches focus on the temporal characteristics of the model and consider rather poor (simple) object models. 2 1 2 2 1 2 valid transaction temporal immutable non temporal migration oo ....

C. Beeri. Formal Models for Object Oriented Databases. In W. Kim et al., editors, , pages 370--395, 1989.

....dictionary graph is an object base schema with only a minimal set of integrity constraints. Class dictionary graphs can be viewed as an adaptation of extended entity relationship diagrams for object oriented design [36] More recently, graphs have been used to model object oriented data bases in [16, 12, 3]. Class dictionary graphs focus only on part of and inheritance relations between classes. One notably absent relation is the uses relation between class operations (see e.g. 29] The call relationships between classes describe important design information, e.g. for checking the Law of ....

Catriel Beeri. Formal models for object-oriented databases. In W. Kim, J. Nicolas, and S. Nishio, editors, Proceedings of 1st International Conference on Deductive and ObjectOriented Databases, pages 370--395, Kyoto, Japan, December 1989. Elsevier.

.... fundamental feature of object databases, useful for supporting object sharing, cyclicity, and update management [5, 6, 17] However, using an object identifier for every object is burdensome even in pure object databases and being able to use structured values as well is important as discussed in [6, 8, 15, 30]. In deductive object databases, using object identifiers for every object is problematic and the pure value oriented approach is considered better in this regard [37] ROL supports not only object identity but also structured values such as functor objects and sets. The user can use object ....

C. Beeri. Formal models for object-oriented databases. In W. Kim, J.M. Nicolas, and S. Nishio, editors, Proceedings of the International Conference on Deductive and ObjectOriented Databases, pages 405--430, Kyoto, Japan, 1989. North-Holland.

....[9] Gulog [19] and Rock Roll [10] Object identity is useful for supporting object sharing and update management. However, using object identifiers for every object is burdensome even in pure object oriented databases and being able to use structured values as well is important as discussed in [4, 11, 15, 24]. In deductive object oriented databases, using object identifiers for every object is problematic and pure value oriented approach is argued better in this regard [32] In this paper, we present the ROL language that has been implemented at the University of Regina. It effectively integrates in ....

C. Beeri. Formal models for object-oriented databases. In W. Kim, J.M. Nicolas, and S. Nishio, editors, Deductive and Object-Oriented Databases, pages 405-- 430, Kyoto, Japan, 1989. North-Holland.

....: point(SELF) closerToOriginThan(P) distFromOrigin(D) point(SELF) distFromOrigin(D1) SELF:radius(R) D2 = D1 R, max(D2,0. 0,D) Figure 3: Class module circle in expanded form 3 Objects We essentially rely on the general definition of an object data model as presented in [1]. However, in this paper we do not discuss types. We consider classes as well as their instances as objects that are implemented as (a collection of) modules with globally visible invariant names. As in [2, 8, 7, 9] instance attributes and class attributes are represented by logical predicates. ....

C. Beeri. Formal models for object-oriented databases. In Deductive and Object-Oriented Databases -- Proc. 1st International Conference DOOD'89, pages 370--395, Berlin, 1989. Springer-Verlag.

....a tuple identifier. Why have relations In principle, relationships could be modeled by making objects that are related to an object x appear as attributes of x. Why then have relations There have been a number of arguments proposed in favor of relations in an object oriented database system [Bee89]. We have discussed some advantages of having relations in the context of objects above. We present a new argument in favor of relations: For relationships of more than two attributes, the approach of making related objects attributes has some drawbacks. Consider a relation supplies with ....

Catriel Beeri. Formal Models for Object-Oriented Databases. Proceedings of DOOD89, pages 370-- 395, December 1991.

....features. Object identity is useful for supporting object sharing, update management, and cyclic object modeling. However, using object identifiers for every object is burdensome even in pure objectoriented databases and being able to use structured values as well is important as discussed in [3, 7, 10, 16]. In deductive object oriented databases, using object identifiers for every object is even problematic and pure value oriented approach is argued better in this regard [23] In this paper, we describes the ROL language that is being developed. The name stands for Rulebased Object Language. The ....

C. Beeri. Formal models for object-oriented databases. In W. Kim, J.M. Nicolas, and S. Nishio, editors, Deductive and Object-Oriented Databases, pages 405--430, Kyoto, Japan, 1989. North-Holland.

.... this approach follows the research on non 1NF relations, in order to extend the data structures of logic programming with sets and complex terms [1, 14, 47, 74] Others attempt to formalize the basic object oriented concepts by developing a new logic to support various features of complex objects [8, 13, 37, 39, 49]. There is also another stream of work which approaches the problem from a programming language perspective. Here the aim is to extend the logic programming languages with some object oriented features such as methods and message passing [19, 25, 50, 75] These proposals are of less interest in ....

C. Beeri. Formal models for object oriented databases. In Proceedings of the First International Conference on Deductive and Object-Oriented Databases, Kyoto, Japan, December 4-6 1989.

....wish to examine multiple processes that operate on common data, perhaps concurrently, we will assume that all such processes Turing machines can read and write this common data tape, DS. Each may have additional tapes to represent local memory. #################################### 3 Both Beeri [Bee90] and Hull [HWW91] have made this observation, although the latter then asserts that the distinguishing feature of [uid] s is that they uniquely identify objects from the real world the objects being identified , while Beeri dismisses them as an implementation concept . In our model, a uid ....

C. Beeri, Formal Models for Object Oriented Databases, in Deductive and ObjectOriented Databases, W. Kim, J. M. Nicolas and S. Nishio (editors), Elsevier Science Publ., North-Holland, 1990.

....[SLR 91] Objects are instances of abstract data types (ADTs) They can be manipulated only by means of their interface, a set of functions. Data are instances of concrete types (such as numbers, strings) and constructed types (such as sets) The distinction from objects is similar to [Bee89] Functions are described by a name and signature (i.e. domain and range types) Functions can be singleor set valued, they are the interface operations of types. The implementation is specified separately (we do not show this here) Notice that we distinguish retrieval functions from methods, ....

....We allow multiple inheritance, that is, types may have more than one supertype. We assume that naming conflicts have already been resolved (for instance, by prefixing function names with type names) Classes. We strictly distinguish types from classes in the following sense (see also [ACO85, Bee89] Types are interface specifications (a collection of functions) whereas classes are containers for objects of some type (type extents) A class C is a collection object (an instance of the metatype class) For each 1 In this paper, we write a . T at the end of an identifier to make clear ....

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C. Beeri. Formal models for object-oriented databases. In Kim et al. [KNN89], pages 370--395. Revised version appeared in "Data & Knowledge Engineering", Vol. 5, North-Holland.

....concepts. This is no surprise, since these new models also typically include ways of nesting objects into others. Some of the models and query languages are either direct followups of the work on nested relations complex objects or at least have been developed in the same research group (such as [16, 41, 112, 111, 49, 33]) Others, even though developed independently, show the same similarities (for example [80, 12, 130, 116, 8, 124, 73] This is a clear indication that the results on complexity, expressive power, optimization, and implementation issues obtained in the context of nested relations complex objects ....

.... DeptRel DeptTup EmpRel EmpTup DeptRel DeptTup (a) b) Figure 2: Example of a forbidden type construction (a) and a solution using functions (b) This solution originates from functional data modeling [117] and has been taken up in many of the recent object oriented approaches [130, 33, 16, 77, 111, 73]. Since by introducing functions instead of just composite structures the objects and the relationships between them (expressed by functions) are separated, the recursion is broken. Pure objectfunction models go one step further: once there is the need to support functions (in order to brake ....

[Article contains additional citation context not shown here]

C. Beeri. Formal models for object-oriented databases. In Kim et al. [65], pages 370--395. Revised version appeared in "Data & Knowledge Engineering", Vol. 5, North-Holland.

....2.1 Basic Concepts Objects are instances of abstract object types (AOTs) They can be manipulated only by means of their interface, a set of functions. Data are instances of concrete types (such as numbers, strings) and constructed types (such as sets) The distinction from objects is equal to [Bee89] Functions are described by a name and signature, they are the interface operations of type instances. The implementation is specified separately. We use the term functions in the general sense including retrieval functions as well as methods, that is, functions with side effects. According to ....

....We allow multiple inheritance, that is, types may have more than one supertype. We assume that naming conflicts have already been resolved (for instance, by prefixing function names with type names) Classes and Views are strictly distinguished from types in the following sense (see also [ACO85, Bee89] Types are interface specifications (a collection of functions) whereas classes are containers for objects of some type (type extents) Each class or view, C, represents a (typed) set of objects and associates a type, the member type(C) to all objects in the set extent(C) The extent of a ....

C. Beeri. Formal models for object-oriented databases. In W. Kim, J.-M. Nicolas, and S. Nishio, editors, Proc. 1st Int'l Conf. on Deductive and Object-Oriented Databases, pages 370--395, Kyoto, December 1989. North-Holland. Revised version appeared in "Data & Knowledge Engineering", Vol. 5, North-Holland.

....model, tuples with an ID attribute defined over this domain represent objects. While this is the way how objects have to be represented internally, we pursued a more abstract view for the data model level: a distinction between (abstract) objects and concrete data values was introduced (see also [Bee89, Bee90] for example) Generalization hierarchies are known from the AI (or semantic data modeling) field, they also appear as inheritance hierarchies in object oriented programming languages (OOPLs) In AI knowledge representation, such hierarchies are described by predicates that allow for the ....

....the set of all possible instances (the domain) The extensional aspect (akin to the current set of tuples in a relation) captures a dynamically changing collection of instances. In general, there might be an arbitrary number (zero, one, or more) of collections over the same schema . Similar to [Bee89, Bee90, HFW90] and others, we introduced the term type to denote the intensional aspects, that is, the description of the interface of the objects that are instance of that type. The term class is used for a collection (an extension) of objects, the members of that class. All members ....

C. Beeri. Formal models for object-oriented databases. In W. Kim, J.- M. Nicolas, and S. Nishio, editors, Proc. 1st Int'l Conf. on Deductive and Object-Oriented Databases, pages 370--395, Kyoto, December 1989. NorthHolland. Revised version appeared in "Data & Knowledge Engineering", Vol. 5, North-Holland.

....we present throughout this paper is based on the COCOON object model. We very briefly review the key concepts of the object model and the algebra, referring to the literature for more details [24, 23] 2. 1 Basic Concepts The COCOON object model is an object function model in the sense of [4, 5]. Its basic constituents are objects, functions, types, and classes: Besides data, which can be atomic (numbers, strings) or constructed (tuples, sets) there are objects that are instances of abstract object types (AOTs) Objects can be manipulated by a set of applicable operations. Functions ....

....relationship that is used for type checking corresponds to the subset relationship of the function sets. Thus, instances of one type are also instances of its supertypes (multiple instantiation) The root of this lattice is the predefined type object. Classes are strictly distinguished from types [4]. Classes are typed collections of objects. So every class c has an associated member type mtype(c) and an actual extension extent(c) the set of objects in the class. We define the extent of a class to include the members of all its subclasses. Thus, objects can be member of multiple classes at ....

C. Beeri. Formal models for object-oriented databases. In DOOD89 [7].

....classes. Then we investigate the transformation of object retrieval and manipulation by comparing COOL with Oracle s relational SQL and the SQL like query interface of ONTOS. 2 The COCOON Model Essentially, the COCOON model as described in [SS90, SLT91] is an object function model in the sense of [Bee89]. It is a core object model, meaning that it is restricted to the essential ingredients: objects, functions, types, and classes. Func 1 Recursive acronym standing for COcoon . Complex Object Orientation based on Nested relations . tions are the generalized abstraction of attributes (stored ....

C. Beeri. Formal models for object-oriented databases. In W. Kim, J.-M. Nicolas, and S. Nishio, editors, Proc. 1st Int'l Conf. on Deductive and Object-Oriented Databases (DOOD), Kyoto, Japan, December 1989. North-Holland.

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C. Beeri. Formal Models for object oriented databases. In Proc. 1st Intl. Conf. on Deductive and object-oriented databases, pages 370--396, 1989.

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C. Beeri. Formal Models for object oriented databases. In Proc. 1st Intl. Conf. on Deductive and object-oriented databases, pages 370--396, 1989.

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Beeri, C. #1989#. Formal Models for Object Oriented Databases. In W. Kim et al., editors, Proc. First Int'l Conf. on Deductive and Object-Oriented Databases, pages 370#395.

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C. Beeri, "Formal Models for Object Oriented Databases", in First International Conference on Deductive and Object Oriented Databases, Ed. W. Kim, pp. 405-430, Kyoto, North-Holland, 1989.

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