C. Lcluse, P. Richard, and F. Vlez. O 2 , an object-oriented data model. In Franois Banchilon, Claude Delobel, and Paris Kanellakis, editors, Building an Object-Oriented Database System: The Story of O 2 , 1992.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....realized on top of the O2 DBMS[11] The goal of this implementation was to add consistency controls to method signatures. Our approach is based on code generation (a pre processor) From in context and out context specification, we generate O2C code (O2C is one of the languages used in O2 DBMS [6, 10]) Then the code is executed in O2 environment. For the programmer, this means that he can extract the code related to integrity and express consistency properties in term of pre and post conditions. A problem with this approach is that integrity rules may be fragmented among different (and ....

C. Lecluse, P. Richard, F. Velez: O2, an object-oriented data model. Proc. of the ACM SIGMOD Conf., Chicago, 1988

....ObjectOriented Database System Manifesto [6] list a number of features which they argue are essential for OO database systems. Parallel to this, a number of formalizations of OO models have been proposed, such as COL [1, 2, 3] F logic [33] HILOG [13] ILOG [29] IQL [4, 5] formalizations of 02 [36, 35], OBJ and related languages [20, 21, 22, 23, 25, 38] OBLOG [15, 19, 17, 43] and CMSL [50, 46] Beeri [9] gives a survey of some issues. Even though these papers are top down, there is not yet any root concept from which they develop their formalization of object orientation. The trees of ....

C. Lcluse, P. Richard, and F. Velez. 02, an object-oriented data model. In J.W. Schmidt, S. Ceri, and M. Missikoff, editors, Advances in Database Technology - EDBT'88, pages 556 562. Springer, 1988. Lecture Notes in Computer Science 303.

.... MQL specific one: MQL allows for incompletely quantified expressions in WHERE clauses (with each non quantified expression E containing attribute att of atom type AT having the semantic EX ISTS a AT: E ) To standardize the representation, expression completion forms the existential closure [29]. After the compilation phase is finished, a correct QEP has been generated and stored within an access module, which already may be executed by the query execution components. We have designed QEPs in such a way that they do not need to undergo any optimization in order to be executable, ....

.... separately (using CSM) The component molecules of the next recursion level are determined by the recursion defining reference attributes, together with the termination condition (UNTIL clause) and the general recursion termination rule for processing the transitive closure (fixed point semantics [29] w.r.t. the set of non recursive component molecules) This level by level evaluation is shown in Example 2.4b for a simple recursive molecule. Example 3.1 combines several operators to create an operator graph. First of all, the left most operator (construction of simple molecules) has to be ....

C. Lcluse, P., Richard, and F. Velez, F., O 2 , an Object-Oriented Data Model, in: Proc. ACM SIGMOD Int. Conf. on Management of Data, Chicago (1988) 424-433.

....dernier principe est leve dans certains cas tres precis tels que l utilisation du langage de requetes. 2.2 D efinition formelle d un mod ele orient e objet Cette section presente la definition formelle d un modele particulier. Cette presentation emprunte beaucoup aux mod eles IQL [AK89] et O 2 [LRV88, LR89a, LR89b]. La plupart des modeles orientes objet possedent les caracteristiques decrites dans cette section. 2.2.1 Types et hi erarchies de classes Les definitions formelles d objet, de type et de hierarchies de classes sont etroitement liees. Un objet consiste en la donnee d une paire (identificateur, ....

C. Lecluse, P. Richard, and F. Velez. O 2 , an Object-Oriented Data Model. In ACM SIGMOD International Conference, May 1988. 17

.... or extensionally defined functions in functional databases) one can distinguish two fundamentally different approaches to bulk type support within a language framework: Built In Bulk Types are provided as first class parameterized type constructors in several programming languages [Sch77, LRV88, OBBT89, NT89] their syntax, type rules, semantics and implementation being hard wired into the language processor and the run time system support. Add On Bulk Types are defined and implemented utilizing standard built in language mechanisms (typing, naming, binding, scoping or recursion) of a ....

....element type. The number of elements, called the cardinality of the relation, is unconstrained. The cardinality of relation variables can vary dynamically, i.e. all relation variables in DBPL programs are mutable values. Most built in bulk types (like those of Pascal R, E or [Sch77, RC87, LRV88] and add on bulk types (collections defined in Smalltalk, Eiffel, Trellis Owl or Modula 3 [GR83, Mey88, SCB 86, CDG 88] define mutable entities. Bulk types in functional languages (Machiavelli, FQL, ADAPTBL or TRPL [OBBT89, Nik88, SSS90, SS91] define pure values and therefore do not offer ....

[Article contains additional citation context not shown here]

C. Lecluse, P. Richard, and F. Velez. O  , an Object-Oriented Data Model. In Proceedings of the ACMSIGMOD International Conference on Management of Data, Chicago, Illinois, pages 424--433, 1988.

....break this restriction and to generalize this mechanism to multilanguage systems. One approach toward a multilanguage persistence system is to content ourselves with a prede ned set of persistent data types for which we can de ne standard representations. An object oriented database system O 2 [16] took this approach and developed several programming languages to access O 2 databases based on a technique to embed query facility for O 2 in various existing programming languages such as C and Lisp [15] Although this approach achieves a degree of multilanguage sharing of databases, it has the ....

C. Lecluse, P. Richard, and F. Velez. O 2 , an object-oriented data model. In Proc. ACM SIGMOD Conference, pages 424-434, 1988.

.... OODB eld focuses largely on modeling static, conceptual entities as objects, despite the fact that OODBs have the potential to be populated with many user de ned arbitrary behaviours, possibly implemented in multiple programming languages (e.g. foreign functions in IRIS [F 87] methods in 1 O 2 [LRV88], and user de ned procedures in POSTGRES [RS87] In IRIS [F 90] and VISION [CS88] userde ned arbitrary behaviours are treated as database objects. However, they are simply collected under a few system de ned function types, capturing little semantics which might help a new user to understand ....

Lecluse, C., Richard, P., and Velez, F. O2, an Object-Oriented Data Model. Proc. 1988 ACMSIGMOD Conference, 424-433.

....onto methods defined for the corresponding classes. The application of a transformation on an R structure instance is analogous to the invocation of a method on the corresponding object. Instances of R structures map onto objects belonging to classes. In implementing VCME we used the OODBMS O 2 [39] because it supports ODMG 93. We have taken particular care to ensure that the functionality of the CMS is not limited to that provided by O 2 . For this, we have developed an interface providing high level functions to manipulate O 2 objects. This interface is built primarily on ODMG ....

C. Lecluse, P. Richard and F. Velez (1988) O 2 : An Object-Oriented Data Model, Proc. ACM SIGMOD, Chicago. 424-433.

....a network to exploit parallelism of activities. All process data (including the SLANG fragments) are stored in an object oriented repository. As the SLANG process engine execute, all modified and newly created process artifacts are stored using the O 2 object oriented database management system [25]. The architecture of the process 48 Current Code Change Document Begin Coding Unit to be Edited OpenFile Request EditorOpenFile EditorFileSaved Unit being Edited Save Compile Request Unit Saved cc Compiled Unit Compilation OK Compilation Errors Found Error free File ....

....[15 16, 18 20] The Transfer CP then moves into state P0 [17] The Deposit CP is then instantiated at [21 22] Between [23] and [24] the Deposit CP begins a transaction. When Deposit tries to access the appropriate objects, however, between [24] and [26] a locking conflict occurs, and a message [25] is generated by the Pern mediator. The particular transaction id, 5, is part of the message so only this 137 Deposit CP is registered for it. Deposit moves from fP1, Idleg into fP0, abortg. This transition generates a working context, 00001002, at [27 28] but also prepares for the abort. ....

P. Richard C. Lecluse and F. Velez. o2, an Object-Oriented Data Model. In Readings in Object-Oriented Database Systems, pages 227--236. Morgan Kaufman, San Mateo CA, 1990.

....in an instance from a class) only if a local definition 4 is not available. This implies that a subclass will inherit the most specific definition of a property in a hierarchy. Our approach to the definition based overriding is shared by most classical object oriented models including O 2 [17], Orion [15] Gemstone [18] C [22] Smalltalk [5] etc. However, in the case of a multiple inheritance, a subclass may be required to inherit a property from more than one superclasses and an inconsistency may result due to the di#erence in implementation of the method or the signature. This ....

....clauses, to determine the inheritability of these clauses using static compilation. This is possible because we adopt a static overriding approach similar to many imperative languages such as C [22] Smalltalk [5] and object oriented databases such as Gemstone [18] Orion [15] and O 2 [17]. Although the inheritability function #m uses negative 138 information, it is easy to see that the concepts of rule locality and inheritability of clauses help eliminate the need for stratification, and thus help improve the overall e#ciency significantly. This should not be confused with ....

C. Lecluse, P. Richard, and F. Velez. O 2 , An Object-Oriented Data Model. ACM Press, 1987.

....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 ....

[Article contains additional citation context not shown here]

C. Lecluse, P. Richard, and F. Velez. 0 , an Object-Oriented Data Model. In F. Bancilhon and P. Buneman, editors, , pages 257--276. Addison-Wesley, 1990.

....useful for many applications. Also, we consider methods . The various features that can be found in the data structure are standard in database models. See, for instance, the survey on Semantic Database Models of Hull and King [25] or recent proposals on object oriented database models, e.g. [12, 22, 33, 34]. 2 The language that we propose is rule based. An important aspect is that it is (to a large extent) declarative . All the user can do is specify statements of the forms: if condition then assertion ; while condition do assertion : These statements can be viewed as deduction ....

C. Lecluse, P. Richard, and F. Velez. O 2 , an Object-Oriented Data Model. In Proc. ACM SIGMOD, 424-434, 1988.

....structural part of OO database to represent the extended database model. Keywords: database semantics, object oriented databases, database modelling. 1 Introduction In spite of considerable research effort directed to the problems of the formalisation of object oriented (OO) database models [16, 3, 6, 10, 14, 23] in the last decade, there is still a lack of a strong theoretical background for OO databases. The main reason for this lies in the rich set of sophisticated data modelling constructs provided by OO database models [6] In this paper we focus on one aspect of the OO database models: a structural ....

....values to include individual and class identifiers. 15 The proposed formalisation uses many ideas presented by some existing formal representations of the OO database model. First, the formalisation is closely related to the formalisation of the O 2 database model proposed by Lecluse at al. in [16], and to the formal presentation of the database model of IQL [3] The paper of Lecluse et al. presents clearly the main features of the OO database model, including the inheritance, methods and types, in a denotational style using the standard notions of interpretations and models. In a similar ....

C. Lecluse, P. Richard, F. Velez, O 2 , an Object-Oriented Data Model, ACM SIGMOD 1988

....stamp. This is possible due to the dynamic format selected for implementing the objects. In parallel, the relationship between stamps is stored in a version graph which records the possible states of the database, thus providing a viewpoint mechanism similar to that of ART [Clayton 85] and of O2 [Lcluse et al. 87] The global version graph is not a tree, since recombination of versions can lead to merged branches as shown on Fig. 5. In the case of merged versions, there is no ambiguity unlike in the case for multiple inheritance in semantic models. In the MOSS system all objects are versioned, including ....

Lcluse C., Richard Ph. and Velez F., O2, An Object-Oriented Data Model, Rapport ALTAIR, Rocquencourt, France, 1987.

....The rule is that an attribute overrides another if it is the same sort of attribute (i.e. single or set valued) and the type is a subclass of the attribute being overridden. This precludes overriding attributes which are atoms or base types. This feature is known as covariance [Lecluse88]. This is the solution used in the righthand side of Figure 3.5, where the components attribute of Spec Configuration is now a set of Spec Components which overrides the components attribute in XConfiguration.The constraint in XConfiguration still works (because the components attribute contains ....

C. Lecluse, P. Richard, and F. Velez. O 2 , an object-oriented data model. Proceedings of the ACM SIGMOD Conference (Chicago, Illinois). ACM, New York, 1988.

....extension of existing evolutionary approaches (e.g. 27, 41, 42, 40, 39, 12, 31, 1, 25, 20, 21] The CMS framework of [35] uses a conceptual (CMS) data model which generalizes semantic (e.g. ER [9] SDM [17] etc. and object oriented data models (e.g. Gemstone [11] Vbase [3] ORION [4] O 2 [23], etc. In particular, the CMS data model is based on a sound characterization of scientific activities that employs the concepts of concrete and abstract representational structures (R structures) In essence, an R structure may be constructed that corresponds to any scientific modeling concept ....

C. Lecluse, P. Richard, and F. Velez. O 2 : An object-oriented data model. In Proc. ACM SIGMOD Int. Conf. on Management of Data, pages 424--433, Chicago, June 1988.

....do not capture several essential features we deem necessary for an abstract database model. But they do introduce a rich set of constraint specification and maintenance tools. The CASE based model proposed in [17] is a semantic network based model developed specifically for the OO language O 2 [53] and Morse. It has limitations, in our opinion, even as an OO modeling tool. It is an example of DBMS dependent data model. It also proposes an automated design procedure of OO database schema from abstract specifications of the models. To model a wide range of future applications such as ....

....Domains and Values In the OR model, there are two types of values basic values and constructed values. Basic values are essentially basic objects and are atomic elements of the corresponding basic domains such as integer, real, string, etc. Many of the existing OO models (e.g. see O 2 model [53] and F logic [47] treat basic values also as objects, some models (e.g. O 2 ) even allow oids for basic values. We believe this is unnatural and make a clear distinction between them. Basic values are just values, distinct from other objects, without any surrogates or ids, and are naturally ....

C. Lecluse, P. Richard, and F. Velez. O 2 , An Object-Oriented Data Model. ACM Press, 1987.

....by their behavior, state and identity. The identity is defined as the sum of the properties of a given object that distinguishes this object from all other existing objects ( KOCO86] The identity property takes into account that objects have an existence independent of their actual value ( LRV90] Thus two objects can be equal, which means having the same value, without being identical, which means being the same object. The object behavior describes how an object acts and how it interacts with the outer world in terms of state changes and method invocations. The state of an object is ....

C. Lecluse, P. Richard, and F. Velez. O 2 , An Object--Oriented Data Model. 1990.

.... be used without inheritance or extensible data types in a relational database [PBRV90] Typically, object oriented databases are used for applications that do not fit the relational model well, such as CAD (computer aided design) Some im18 plementations of object oriented databases include O 2 [LRV88] and Gemstone [MSOP86] 8 History and Current Status We developed schema and tuple trees in 1989 when we first developed Qddb. At that time, Qddb was implemented in around 10,000 lines of C code and performed very basic searches and operations. Qddb was released to the public, but the ....

C. Lecluse, P. Richard, and F. Velez. O2: An Object-Oriented Data Model. In Proceedings of the ACM International Conference on the Management of Data, pages 424--433, 1988.

....Close integration of the concepts of the class identifier and the structural type provides a clear method for the definition of type interpretation, which can now be defined as a straightforward extension of the class interpretation. The interpretation of a type t 2 V T , denoted by I(t) is [3, 30]: 1. t 2 OC = I(t) I c (t) 2. t = fsg = I(t) fo; o I(s)g, 3. t = A 1 :t 1 , An :t n ] I(t) f[A 1 :v 1 , An :v n ] v i 2 I(t i )g. This definition of the type interpretation specifies the membership relationship between ground o values and types. Let v 2 VD and t 2 V T . ....

C. Lecluse, P. Richard, F. Velez, O 2 , an Object-Oriented Data Model, Proc. of the ACM Conf. on Management of Data, 1988, pp. 424-433.

....introduction of time in an object oriented context but not on a formal basis. By contrast, a great amount of theoretical research is being carried on in the area of non temporal object oriented programming languages and databases, and theoretical foundations have been established [AHV95, Bee89, LRV90] In particular, issues concerning type systems and type checking have been widely investigated in a non temporal object oriented framework [BF91, Car88] 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 Table 2. 1 only two dimensions: whether values are distinguished from objects (and types from classes at the intensional level) Bee89, LRV90] 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. Table2.1: Comparison among temporal o o data models (I) Concerning the temporal aspects, ....

[Article contains additional citation context not shown here]

C. Lecluse, P. Richard, and F. Velez. 0 , an Object-Oriented DataModel. In F. Bancilhon and P. Buneman, editors, , pages 257--276. Addison-Wesley, 1990.

....is an evidence of this trend. Important work on dynamic aspects of databases includes practically oriented research on behavior modeling and transaction design [9 11,24,27,28] encapsulating both structural and behavior data, e.g. object oriented databases including Gemstone [15] Vbase [6] O 2 [25,26], IRIS [7] etc. and also includes theoretical studies on transactions as specification languages [2,4] and on dynamic integrity constraints [13,16,32,33] Previous studies on modeling database behavior can be roughly categorized into two approaches. One uses behavioral constructs to describe ....

C. Lecluse, P. Richard, and F. Velez. O 2 : An object-oriented data model. In Proc. ACM SIGMOD Int. Conf. on Management of Data, pages 424--433, Chicago, June 1988.

No context found.

C. Lcluse, P. Richard, and F. Vlez. O 2 , an object-oriented data model. In Franois Banchilon, Claude Delobel, and Paris Kanellakis, editors, Building an Object-Oriented Database System: The Story of O 2 , 1992.

No context found.

C. Lecluse, P. Richard, and F. Veles. O , an Object-Oriented Data Model. In Proceedings of the Workshop on Database Programming Languages, Roscoff, France, September 1987. Also in [KL89].

No context found.

Christopher L'ecluse, Philippe Richard, and Fernando Velez. O 2 , an Object Oriented Data Model. Technical Report Altair 10-87, Altair, BP 105; 78153 Le Chesnay Cedex; France, September 1987.

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