Randel J. Peters and M. Tamer Ozsu. An axiomatic model of dynamic schema evolution in objectbase systems. ACM Trans. Database Syst., 22(1):75--114, 1997.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....field, two main approaches were followed to ensure consistency in pursuing the semantics of change problem. The first approach is based on the adoption of invariants and rules, and has been used, for instance, in the ORION [6] and O 2 [20] systems. The second approach, which was proposed in [36], is based on the introduction of axioms. In the former approach, the invariants define the consistency of a schema, and definite rules must be followed to maintain the invariants satisfied after each schema change. Invariants and rules are strictly dependent on the underlying object model, as ....

R. J. Peters and M. T. Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transactions On Database Systems, 22(1):75--114, 1997.

....database field and, more precisely, in the subfield that deals with the problem of schema evolution. The problem has two aspects: the semantics of changes (i.e. their effects on the schema) and the change propagation (i.e. the propagation of the schema changes to the underlying existing instances) [18]. Both aspects have been studied extensively for the relational and the object oriented data models, in the temporal and the non temporal variants [19] The results have been often incorporated into commercial or prototype database systems (e.g. Orion [3] O 2 [26] Cocoon [24] F2 [1] and ....

# Peters, R.J., zsu, M.T. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems, ACM TODS, 22(1), pp. 75-114.

....bad ever happens and can be captured by the formula 2 : E v ) On the other hand, liveness constraints saying that something good will happen can be expressed by existential temporal formulas: 3 : E v ) Schema evolution. We consider here a simplified case of conceptual schema evolution [38, 20, 35], which can be called a monotonic approach. This allows only for changes in the schema such that the resulting conceptual schema is compatible with the previous global constraints. Let and p be atomic formulas, or possibly a Boolean combination of atomic formulas, which introduce, respectively, ....

R. J. Peters and M. T. Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transactions On Database Systems, 22(1):75--114, 1997.

....particular, two main approaches were followed to ensure consistency in pursuing the semantics of change problem. The first approach is based on the adoption of invariants and rules, and has been used, for instance, in the ORION [4] and O 2 [12] systems. The second approach, which was proposed in [24], is based on the introduction of axioms.In the former approach, the invariants define the consistency of a schema, and definite rules must be followed to maintain the invariants satisfied after each schema change. Invariants and rules are strictly dependent on the underlying object model, as ....

R.J.PetersandM.T. Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transaction on Database Systems, 22(1):75--114, 1997.

....field, two main approaches were followed to ensure consistency in pursuing the semantics of change problem. The first approach is based on the adoption of invariants and rules, and has been used, for instance, in the ORION [2] and O [1] systems. The second approach, which was proposed in [32] and developed in the context of the TIGUKAT [33] is based on the introduction of axioms. In the former approach, the invariants define the consistency of a schema, and definite rules must be followed to maintain the invariants satisfied after each schema change. In the latter approach, a sound ....

R. J. Peters, M. T. Ozsu, An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems, ACM Transactions on Database Systems 22 (1) (1997) 75--114.

....to require that at any moment of time the company has at least one employee: # # (Employee ##) 3. 3 Schema evolution The problem of schema evolution arises in the context of long lived database applications, where stored data are considered worth surviving changes in the database schema [32, 14, 30]. According to a widely accepted terminology [26] a database supports schema evolution if it permits modifications of the schema without the loss of extant data. We consider here a simplified case of conceptual schema evolution, which can be called a monotonic approach. This allows only for ....

R. J. Peters and M. T. Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transactions On Database Systems, 22(1):75-- 114, 1997.

....to require that at any moment of time the company has at least one employee: 2 : Employee v ) 3. 3 Schema evolution The problem of schema evolution arises in the context of long lived database applications, where stored data are considered worth surviving changes in the database schema [32, 14, 30]. According to a widely accepted terminology [26] a database supports schema evolution if it permits modifications of the schema without the loss of extant data. We consider here a simplified case of conceptual schema evolution, which can be called a monotonic approach. This allows only for ....

R. J. Peters and M. T. Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transactions On Database Systems, 22(1):75-- 114, 1997.

....case) two main approaches were followed to ensure consistency in pursuing the semantics of change problem. The first approach is based on the adoption of invariants and rules, and has been used, for instance, in the ORION [4] and O 2 [12] systems. The second approach, which was proposed in [25], is based on the introduction of axioms. In the former approach, the invariants define the consistency of a schema, and definite rules must be followed to maintain the invariants satisfied after each schema change. Invariants and rules are strictly dependent on the underlying object model, as ....

R. J. Peters and M. T. Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transaction on Database Systems, 22(1):75--114, 1997.

....eld, two main approaches were followed to ensure consistency in pursuing the semantics of change problem. The rst approach is based on the adoption of invariants and rules, and has been used, for instance, in the ORION [3] and O 2 [11] systems. The second approach, which was proposed in [22], is based on the introduction of axioms. In the former approach, the invariants de ne the consistency of a schema, and de nite rules must be followed to maintain the invariants satis ed after each schema change. In the latter approach, a sound and complete set of axioms (provided with an ....

R. J. Peters and M. T.  Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transaction on Database Systems, 22(1):75-114, 1997.

....case) two main approaches were followed to ensure consistency in pursuing the semantics of change problem. The rst approach is based on the adoption of invariants and rules, and has been used, for instance, in the ORION [4] and O 2 [12] systems. The second approach, which was proposed in [22], is based on the introduction of axioms. In the former approach, the invariants de ne the consistency of a schema, and de nite rules must be followed to maintain the invariants satis ed after each schema change. Invariants and rules are strictly dependent on the underlying object model, as they ....

R. J. Peters and M. T.  Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transaction on Database Systems, 22(1):75-114, 1997.

....transition support demands that applications may continue to access the database as if no temporal support had been added, or else, take into account this schema modification. This situation is a rather simple case of schema evolution. Our approach to handle it is similar to those described in [9, 10]. More precisely, three steps are followed. Firstly, the schema is modified. Next, the database is converted to fit the new schema (see section 5.1) Lastly, an updatable snapshot view of the database is introduced. Contrarily to [10] and other related works where the issue of schema evolution ....

R. Peters and M.T. Ozsu. An axiomatic model of dynamic schema evolution in objectbase management systems. ACM TODS, 22(1), 1997.

....of any implementation details, including the internal structure of objects. The TIGUKAT model allows dynamic type, class, behavior, and function creation, modification, and 3 TIGUKAT TYPE SYSTEM 4 deletion. The issues related to schema evolution in the TIGUKAT object model are discussed in [P O95a] and [P O95b] Persistence in TIGUKAT is orthogonal (independent of type) OPS 95] There are also some additional considerations about TIGUKAT persistence related to the structure of the model (for example, the type and the class of a persistent object have to be persistent as well) ....

Randal J. Peters and M. Tamer Ozsu, An axiomatic model of dynamic schema evolution in objectbase management systems, Tech. Report TR 95-02, Department of Computer Science, University of Manitoba, April 1995.

....a special purpose data translation language. This approach is a powerful one, but creation of the transformer is a manual process. More recent database systems generate transformation functions based upon the changes made to the type definitions. Orion [2, 10] GemStone [15] O 2 [7] and Tigukat [16] are object oriented database systems that provide some evolution support. In these systems, evolution is defined in terms of primitive structural changes isolated to individual type definitions, such as adding instance variables to a class, removing instance variables from a class, and renaming ....

Randal J. Peters and M. Tamer Oszu. An axiomatic model of dynamic schema evolution in objectbase systems. ACM Transactions on Database Systems, 22(1):75--114, March 1997.

.... a magnitude of formal models for the description of the single components (e.g. Wir90] data type component, Gog94] object component, Har87] dynamic components) and on the other hand there are many approaches which deal with schema modification and database evolution [BKKK87, FMZ 95, Odb95, PO97, SZ87, Zic92] However, only few approaches (as for example [PO97] apply formal description techniques to schema modification. In this paper we try to integrate parts of both of these research directions by combining well known formal description techniques in a schema modification framework. ....

.... (e.g. Wir90] data type component, Gog94] object component, Har87] dynamic components) and on the other hand there are many approaches which deal with schema modification and database evolution [BKKK87, FMZ 95, Odb95, PO97, SZ87, Zic92] However, only few approaches (as for example [PO97] apply formal description techniques to schema modification. In this paper we try to integrate parts of both of these research directions by combining well known formal description techniques in a schema modification framework. The rest of the paper is structured as follows. Section 2 deals with ....

R. J. Peters and M. T. Ozsu. An axiomatic model of dynamic schema evolution in objectbase systems. In TODS 22(1), 1997.

No context found.

R.J. Peters and M.T. Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transactions on Database Systems, March 1997. To appear.

No context found.

R.J. Peters and M.T. Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transactions on Database Systems, 22(1):75--114, March 1997.

No context found.

Randel J. Peters and M. Tamer Ozsu. An axiomatic model of dynamic schema evolution in objectbase systems. ACM Trans. Database Syst., 22(1):75--114, 1997.

No context found.

R. J. Peters and M. T. Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transaction on Database Systems, 22(1):75--114, 1997.

No context found.

Ozsu M. T. Peters R. J. An axiomatic model of dynamic schema evolution in objectbase systems. ACM Transactions on Database Systems, 22(1):75--114, 1997.

No context found.

R. J. Peters and M. T. Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transaction on Database Systems, 22(1):75--114, 1997.

No context found.

R.J.Peters, M.T.zsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. TODS 22(1), 1997 75-114

No context found.

R.J.Peters, M.T.zsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. TODS 22(1), 1997 75-114

No context found.

R. J. Peters, M. T. zsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. TODS 22(1), 1997 75-114.

No context found.

R. J. Peters and M. T. Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transaction on Database Systems, 22(1):75--114, 1997.

No context found.

R. J. Peters and M. T. Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transaction on Database Systems, 22(1):75--114, 1997.

No context found.

R. J. Peters, M. T. Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transactions on Database Systems, 22(1), pp. 75--114, 1997.

No context found.

R. J. Peters and M. T. Ozsu, "An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems", ACM Transactions on Database Systems, Vol. 22, No. 1, pp. 75-114, 1997.

No context found.

Peters, R. J., Ozsu, M. T., "An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems", ACM Transactions on Database Systems, Vol. 22, No. 1, March 1997, pp. 75-114

No context found.

R.J.Peters, M.T.zsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. TODS 22(1), 1997 75-114

No context found.

R.J.Peters, M.T.zsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. TODS 22(1), 1997 75-114

No context found.

R. J. Peters and M. T. Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transaction on Database Systems, 22(1):75--114, 1997.

No context found.

Peters, R.J. and Oszu, M.T., An Axiomatic Model of Dynamic Schema Evolution in ObjectBase Systems.

No context found.

R. J. Peters and M. T. Ozsu. An Axiomatic Model of Dynamic Schema Evolution in Objectbase Systems. ACM Transaction on Database Systems, 22(1):75--114, 1997.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC