Maier, D. / Stein, J. "Development and implementation of an Object-Oriented DBMS" From "Readings in object-oriented database systems (ed. Zdonik, S. B. / Maier, D.)"I SBN 055860 -000-0; Morgan Kaufmann publishers.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....architecture choice for persistent object systems, and studies comparing object and page based client cache designs. Many persistent object systems use the more traditional page based architecture where all interaction between clients and servers takes place at the granularity of individual pages [7, 11, 12, 1]. Other systems [9, 5] use object server architectures but do not specifically address the problem of installation reads. Dewitt et al. 6] is one of the first studies that investigated the design choices for a persistent object system architecture. The study focused on the question of ....

D. Maier and J. Stein. Development and implementation of an objectoriented dbms. In B. Shriver and P. Wegner, editors, Research Directions in Object-Oriented Programming. MIT Press, 1987.

....grouped together into a single file or table. This is the only grouping supported directly by the system and is the basis for queries in these systems. By contrast, some object oriented databases support user defined sets that group together specific objects of the same type (for example, GemStone[12, 47, 48]) and we would like to support queries over these user defined sets. In such a system, an object can be an element of more than one user defined set. For example, consider a database containing objects representing employees and departments. Each department could contain a set of employees and if ....

....traditional relational databases. The work done in object oriented databases is more closely related to our work. Such systems start with a general object oriented programming language and add support for fast associative access to collections of objects. Some representative systems are GemStone[12, 47, 48], O 2 [23, 24] Orion[4, 36, 37] and ObjectStore[40, 52] Work specifically dealing with 91 indexing falls into two categories: 1. Indexing schemes based on the structure of an object (that is, the values of instance variables) We will call these path based indexing schemes. 2. Indexing ....

David Maier and Jacob Stein. Development and implementation of an object-oriented DBMS. In B. Shriver and P. Wegner, editors, Research Directions in Object-Oriented Programming. MIT Press, 1987. Also in S. Zdonik and D. Maier, eds., Readings in ObjectOriented Database Systems.

....hand, we have to create the classes that will be used during the animation. The last statement requires an interpreted language, such as Smalltalk, that allows to create the specification classes at execution time. We have chosen the OODBMS (Object Oriented Data Base Management System) GemStone [Maier86] [Stein91] for implementing a first prototype of the prototyping tool. GemStone was designed by extending Smalltalk with the main DBMS features. So Gemstone provides features such as persistence, multi user connections and functions for data migration that are required when there are changes on ....

D. Maier and J. Stein. "Development and Implementation of an Object-Oriented DBMS". OOPSLA'86 Proceedings (ACM). October 1986.

....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 ....

....can be shared by the object 6, VAL I3 (6) while the object value VAL I3 (6) VAL I2 (4) 3,36,credit can be shared by the object 9, VAL I9 (6) Figure 4.2] 10 5. Classes and Inheritance A further concept supported by GROOVY is structural inheritance between classes of objects [5, 6, 7, 8, 13, 17]. In GROOVY, to every object schema there corresponds a class schema and the set of class schemas induces an inheritance lattice. Classes are just instances of class schemas. The advantage of GROOVY over other object oriented data models [5, 6, 7, 17] is that we have used hypergraphs as a single ....

[Article contains additional citation context not shown here]

MAIER D., AND STEIN J. 1987. Development and implementation of an object-oriented DBMS. In Research Directions in Object-Oriented Programming (eds. Shriver B. & Wegner P.), MIT Press, Cambridge Mass., pp. 355-392.

....models. The popular semantic models include the E R model, the functional data model (FDM) and the semantic database model. Further details on semantic data models may be found in [HAM81, POT89] while related work can be found in the area of data modeling in object oriented database systems [MA187, BAN87] 3.2 Framework In this subsection we informally describe the framework for a database that can handle structured and unstructured data belonging to heterogenous datasets. A spatial database is a collection of spatial and aspatial entities or objects. These entities correspond to the ....

D. Maier and J Stein, Development and Implementation of an Object-oriented DBMS, Research Directions in Object-oriented programming, 1987.

....relevant to the issue of encapsulation and inheritance supported by some existing object oriented systems. The systems reviewed are: GEMSTONE [2] EXODUS [3] ORION [20] ENCORE [34] POSTGRES [35, 36] STARBURST [22] IRIS [10] and O 2 [9] GEMSTONE is an object based system developed at Servio [2, 23] whose basic architecture distinguishes two main subsystems; the GEM Server process for query evaluation and the Stone Monitor for allocating object identifiers in blocks and coordinating commit activity. Its object oriented database language (OPAL) is used for data definition, data manipulation ....

D. Maier and J. Stein. Development and implementation of an object-oriented dbms. In Proceedings of the first ACM Conference on Object- Oriented Programming Systems, Langs., and Applications, volume 21(11), pages 167--185. SIGPLAN Notices, 1986.

....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 is known as inheritance ....

....such as locality of method 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 ....

D. Maier and J. Stein. Development and implementation of object-oriented DBMS. In B. Shriver and P. Wegner, editors, Research Directions in Object-Oriented Programming, pages 355--392, Cambridge, MA, 1987. MIT Press.

....or with writing time consuming test programs to verify that the database is in fact in a consistent state after the execution of the application code. Support from existing databases is mostly in the form of a built in pre de ned set of consistency de nitions, such as referential integrity [MS90] programming language kinds of consistency de nitions [VD91, AH90] such as assertions and exception handling mechanism in languages like C , Java, Ada, or domain constraints over only a subset of types such as constraints on collection types [SHO95] Relational database systems (RDBs) o er some ....

D. Maier and J. Stein. Development and Implementation of an Object-Oriented Database System. In Readings in Object-Oriented Database Systems, pages 167-185, 1990.

....the implementation of these algorithms is difficult and frequent modifications can reduce the performance of the system significantly in any case. ffl Replication. The replication of mappings can easily be carried out in the same way as using hash tables. B trees are used in GemStone [MS87] and in SHORE [CDF 94] to implement logical OIDs. 3.2 Direct Mapping Index based mapping techniques usually find handles by comparing OIDs. In this section, we discuss a technique that encodes the address of the handle into the logical OID. The rational behind this approach is that handles ....

D. Maier and J. Stein. Development and implementation of an object-oriented DBMS. In B. Shriver and P. Wegner, editors, Research Directions in Object-Oriented Programming, pages 355--392, Cambridge, MA, 1987. MIT Press.

.... extended to include more expressive models, such as nested [S 89, Kor88] and network models [RR85, R 83] Object oriented databases are extensible systems which support (among other features) abstract data types, type inheritance (subtyping) methods and late binding, and object identity [MS87, BDK91, ZW86, MD90, B 87] The extensibility of object oriented databases is founded on the ability to extend the data model through abstract data types and the inheritance structure. In particular, the ability to define new abstract data types provides extensibility in the database modelled ....

David Maier and Jacob Stein. Development and Implementation of an Object-Oriented DBMS. In B. Shriver and P. Wegner, editors, Research Directions in Object-Oriented Programming, pages 355--392. MIT Press, Cambridge, MA, 1987.

....of the entries of an over full node into the new node, only the last entry is moved. Similar optimizations for insertions in ascending order were incorporated in the AP tree [SG89] in the context of temporal databases. Examples of systems that support logical OIDs and use B trees are Gemstone [MS87] SHORE [CDF 94] and Oracle8 [LMB97] 2.2.2 Mapping logical OIDs with hash tables As an alternative to a B tree, a hash table can be used to map logical OIDs. A variety of different hashing techniques that can be used for this purpose have been described in the literature; see, e.g. ....

Maier D, Stein J (1987) Development and implementation of an object-oriented DBMS. In: Shriver B, Wegner P (eds) Research Directions in Object-Oriented Programming. MIT Press, Cambridge, Mass., pp 355--392

....combine the modelling power of object based programming models with traditional database concepts such as persistence, data sharing, consistency, resiliency and optimized query access. A number of object oriented data models and languages have been proposed ( Shi81] Ban87a] Ban87b] Row87] [Mai87], Lec88] Car88] but no single model or language has emerged as a standard for object oriented databases. Our model supports object identity, abstract data types with 1 type inheritance, and encapsulation of behavior and state, as modelling capabilities present in most object oriented ....

....for querying in object oriented databases by supporting the concepts of object identity, abstract data types, type inheritance and typed collections distinct from the type hierarchy. Unlike other languages proposed for object oriented databases (e.g. Zan83] Car88] Osb88] Ban87a] Ban88] [Mai87]) we support all of these concepts and still provide full associative access to the database, including a unique join capability. We discuss our work in relation to previous models and languages in the next section; then, in Sections 3 and 4, present our object oriented data model and our algebra ....

[Article contains additional citation context not shown here]

David Maier and Jacob Stein. Development and Implementation of an Object-Oriented DBMS. In B. Shriver and P. Wegner, edi26 tors, Research Directions in Object-Oriented Programming, pages 355--392. MIT Press, Cambridge, MA, 1987.

.... schedules, work orders, processes, and robotics programs) The difficulty with view management in object oriented systems spans not only updates to views which are a problem even in traditional databases but also the creation of views due to the added complexities of the object paradigm [25, 28, 32]. To successfully implement this technology for production functions and reap its promised benefits for AIME, new view creation and management techniques are required for object oriented systems. Section 5 discusses an approach to a solution. The mapping from a base object model to a view may be ....

D. Maier, and J. Stein, "Development and Implementation of an Object- Oriented DBMS", ResearchDirectionsinObject-OrientedProgramming, editors B. Shriver and P. Wegner, MIT Press, 1987.

....To reason about the use of variable x using the specification of its type , we need to impose additional constraints on the subtype relation. Now consider the case of an environment of shared mutable objects, such as is provided by object oriented databases (e.g. Thor [Liskov 1992] and Gemstone [Maier and Stein 1990]) In fact, it was our interest in Thor that motivated us to study the meaning of the subtype relation in the first place. In such systems, there is a universe containing shared, mutable objects and a way of naming those objects. In general, lifetimes of objects may be longer than the programs ....

Maier, D. and Stein, J. 1990. Development and implementation of an object-oriented DBMS. In S. Zdonik and D. Maier (Eds.), Readings in Object-Oriented Database Systems, pp. 167--185. Morgan Kaufmann.

....of the entries of an over full node into the new node, only the last entry is moved. Similar optimizations for insertions in ascending order were incorporated in the AP tree [SG89] in the context of temporal databases. Examples of systems that support logical OIDs and use B trees are Gemstone [MS87] SHORE [CDF 94] and Oracle8 [LMB97] 2.2.2 Mapping Logical OIDs with Hash Tables As an alternative to a B tree,ahashtablecanbeusedto 4 R. Braumandl et al. a, 3.2) b, 1.2) c, 2.1) d, 4.1) g,5.1) h, 2.2) i, 1.1) g,5.1) e, 3.1) b, 1.2) f,4.2) d, 4.1) c, 2.1) a, ....

D. Maier and J. Stein. Development and implementation of an object-oriented DBMS. In B. Shriver and P. Wegner, editors, Research Directions in ObjectOriented Programming, pages 355--392, Cambridge, MA, 1987. MIT Press.

....via x. To reason about the use of variable x using the specification of its type , we need to impose additional constraints on the subtype relation. Now consider the case of an environment of shared mutable objects, such as is provided by object oriented databases (e.g. Thor [26] and Gemstone [29]) In fact, it was our interest in Thor that motivated us to study the meaning of the subtype relation in the first place. In such systems, there is a universe containing shared, mutable objects and a way of naming those objects. In general, lifetimes of objects may be longer than the programs ....

David Maier and Jacob Stein. Development and implementation of an object-oriented dbms. In S.B. Zdonik and D. Maier, editors, Readings in Object-Oriented Database Systems, pages 167--185. Morgan Kaufmann, 1990.

....semantics they provide as compared to attributes. For instance, regardless of their actual procedural implementation the semantics of methods may be equivalent to queries (in some object oriented database systems the operators of the query language are even provided as methods, e.g. GemStone [16]) Furthermore, in object oriented database systems with extensible data models, the operations of new data model primitives may become visible through methods. Complex and expensive external operations stemming from complex application domains, like document processing, scientific or multimedia ....

D. Maier, J. Stein: "Development and implementation of an object-oriented dmbs", Readings in Object-Oriented Database Systems, pp. 167--185, Morgan Kaufman, 1990.

....x. To reason about the use of variable x using the specification of its type , we need to impose additional constraints on the subtype relation. Now consider the case of an environment of shared mutable objects, such as is provided by object oriented databases (e.g. Thor [Lis92] and Gemstone [MS90] In such systems, there is a universe containing shared, mutable objects and a way of naming those objects. In general, lifetimes of objects may be longer than the programs that create and access them (i.e. objects might be persistent) and users (or programs) may access objects concurrently ....

Maier, D. and Stein, J. Development and implementation of an object-oriented DBMS. In Zdonik, S. and Maier, D., editors, Readings in Object-Oriented Database Systems, pages 167--185. Morgan Kaufmann, 1990.

....system, for which clients expect continuous operation despite faults and transmission delays. So, though originally motivated to support distributed file systems, weak sets are more generally abstractions useful for both persistent object repositories, e.g. Cricket [14] EOS [5] Gemstone [10], and Thor [8] see [1] for others) and wide area information systems and their applications, e.g. the World Wide Web (WWW) 2] WAIS [7] and Gopher[11] Using an iterator like operation to perform search and retrieval is common in these systems. 1.3 Roadmap The rest of the paper is structured ....

David Maier and Jacob Stein. Development and implementation of an objectoriented DBMS. In S.B. Zdonik and D. Maier, editors, Readings in Object-Oriented Database Systems, pages 167--185. Morgan Kaufmann, 1990.

....This 2 In an object oriented framework, classes and instances of a class are all treated as first class objects. Through an object oriented query interface, such as those provided in OODBMS systems, users may query over classes and instance objects of the classes in the same manner [4, 15, 3]. is significant in that it permits temporal queries, touted by some as a key ability for knowledge discovery systems [11] Relational systems can also exploit the temporal ordering of transactions, but this adds another piece of information that needs to be stored and maintained for each ....

D. Maier and J. Stein. Development and implementation of an object-oriented DBMS. In S.Zdonik and D.Maier, editors, Readings in OODB Systems. 1990.

.... and hierarchical, have been found insufficient [Dit89, SRL 90] An architecture better suited for these application areas is that of object oriented database management systems (OODBMS) ABD 89, Kim90, ZM90, AWSL90] By now, there exist a considerable number of OODBMSs, e.g. HZ87, MS87, AH87, CDG 90, KGBW90, WLH90, Deu90, Wad90, Ver91, Obj91] Some of them are available as prototypes, others as commercial products. There are several issues involved when designing an OODBMS. Our approach was decisively influenced by the following two aspects: First, due to different and ....

D. Maier and J. Stein. Development and Implementation of an Object-Oriented DBMS. In B. Shriver and P. Wegner, editors, Research Directions in Object-Oriented Programming, pages 355--392. MIT Press, 1987.

....to forgo safety for improved performance. Many systems, e.g. 4, 12, 3] allow the application code to directly manipulate database objects; ODMG [7] also follows this approach because it allows methods of shared objects to be written in various unsafe programming languages. O2 [10] and GemStone [16] store methods in the database, which means that it is possible to guarantee that the right code runs in response to application calls. However, the languages provided by O2 for method definition are not safe (for example, one of these languages is an extension of C) GemStone does better since ....

D. Maier and J. Stein. Development and implementation of an object-oriented DBMS. In B. Shriver and P. Wegner, editors, Research Directions in ObjectOriented Programming. MIT Press, 1987.

No context found.

Maier, D. / Stein, J. "Development and implementation of an Object-Oriented DBMS" From "Readings in object-oriented database systems (ed. Zdonik, S. B. / Maier, D.)"I SBN 055860 -000-0; Morgan Kaufmann publishers.

No context found.

D. Maier and J. Stein, \Development and Implementation of an Object-Oriented DBMS," in Shriver B. and P. Wegner (eds), Research Directions in Object-Oriented Programming, MIT Press, Cambridge, MA, 1987.

No context found.

D. Maier and J. Stein, \Development and Implementation of an Object-Oriented DBMS," Research Directions in Object-Oriented Programming, Shriver B. and P. Wegner Eds, MIT Press, Cambridge, MA, 1987.

First 50 documents  Next 50

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