F. Bancilhon, C. Delobel, and P. Kanellakis (ed.), "Building an object-oriented database system: the story of O2", Morgan Kaufmann, San Mateo, California, 1992.  Home/Search   Document Not in Database   Summary   Related Articles   Check

.... in advanced database applications, it is important to extend our domain of study from relational database systems to object oriented database systems and investigate the mechanisms for knowledge discovery in object oriented databases (00DBs) 43, 29] Object oriented data models and systems [5, 6, 31, 33] embody rich data structures and semantics in the construction of complex databases, such as complex data objects, class subclass hierarchies, class composition hierarchies, property inheritance, methods and active data, etc. This not only brings the power and flexibility to the system but also ....

....of relevant data, and the background knowledge, proceeds as follows. First, a data retrieval process is initiated to collect the set of relevant data, which corresponds to the processing of an object oriented database query (by some interesting object oriented query processing techniques, such as [6, 32, 33, 51, 44]) Second, generalization is performed on the set of retrieved data, which corresponds to the generalization of complex data objects, for which a set of generalization operators should be developed. Third, an object cube based generalization is performed to generalize and compress the set of ....

F. Bancilhon, C. Delobel, and P. Kanellakis. Building an Object-Oriented Database System: The story of 02. Morgan Kaufmann, 1992.

....query processing and optimization, and user interfaces. In [10] an overview of these aspects of the Lore system is provided, as well as other novel features such as dynamic structural sum maries and seamless access to data from external sources. Lorel, for Lore Language, is an extension of OQL [5, 3] that introduces extensive type coercion and powerful path expressions for effectively querying semistructured data. Current research on semistructured data does not exam ine the dynamic aspects extensively. The following issues may be identified as gaps: Extremely flexible but also extremely ....

F. Bancilhon, C. Delobel, and P. Kanellakis. Building an Object-Oriented Database System: The Story of 02. Morgan Kaufmann, San Francisco, California, 1992.

....it as needed) depends on the concrete system. Our discussion focusses on the schema evolution approach because it is most relevant to our work; a problem with the versioning approach is the huge amount of storage it requires. The scheme evolution approach is used in the commercial systems O2 [15, 3], GemStone [23, 8] Objectivity DB [22] and Versant [25] and in the research systems Orion [4] OTGen [18] and PJama [2, 14] and is the only approach available in commercial RDBMS. Very few of these systems support general transforms and lazy conversion: Gemstone and Orion do not support ....

F. Bancilhon, C. Delobel, and P. Kanellakis, editors. Building an Object-Oriented Database System - The Story of O2. Morgan Kaufmann Publishers, 1992.

....it as needed) depends on the concrete system. Our discussion focusses on the schema evolution approach because it is most relevant to our work; a problem with the versioning approach is the huge amount of storage it requires. The scheme evolution approach is used in the commercial systems O2 [15, 3], GemStone [23, 8] Objectivity DB [22] and Versant [25] and in the research systems Orion [4] OTGen [18] and PJama [2, 14] and is the only approach available in commercial RDBMS. Very few of these systems support general transforms and lazy conversion: Gemstone and Orion do not support ....

F. Bancilhon, C. Delobel, and P. Kanellakis, editors. Building an Object-Oriented Database System - The Story of O2. Morgan Kaufmann Publishers, 1992.

..... 33 9.5 Intersection, Union, and Difference . 34 9.6 Compression Functions . 35 10 Conclusions 35 1 Introduction Object data models [1, 5, 36, 4] have been used to model numerous applications ranging from multimedia applications[11, 12] financial risk applications[10] and logistics and supply chain management applications [2] weather applications [14] as well as many others. Many of these applications naturally need to represent and ....

F. Bancilhon, C. Delobel, and P. Kanellakis, editors. Building an Object-Oriented Database System: The Story of O . Morgan Kaufmann, Los Altos (CA), 1991.

....[SS89] We use a schema specification language (called OASIS) that includes facilities for constraint and query definition, object manipulation, and transaction definition. The features of the object manipulation language are common to object oriented database technology (cf. the O2 system [BDK92] namely, bounded iteration, heterogeneous collections, object creation, and nil values. The specification language is mapped by a schema translator toasimpleformalmodel of objects in higher order logic. This model imitates the type tagged memory structure of an implementation and is su#cient ....

....of these tables. These include non nil requirements (c 1 , c 2 , c 3 ) and extent constraints (c 4 , c 5 ) see [BFW98] Constraint c 6 asserts that all links in a composite node should link nodes within that same composite node. The command language we use is similar to the O2C update language [BDK92] and consists of a small number of commonly used language constructs. Atomic updates are object creation, and variable and attribute update. There is no object deletion, because persistence by reachability is used (as in the O2 system [BDK92] Compound commands are formed using sequential ....

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F. Bancilhon, C. Delobel, and P. Kanellakis, editors. Building an Object-oriented Database System: The Story of O2. Morgan Kaufmann, 1992.

....type. Finally, Section 6 presents conclusions and introduces some extensions which are under way to extend the NAOS event model and to improve the eciency and the modularity of the event detection process. 2 NAOS Overview One of the enhancements of the object oriented database system 02 [1] used in the GOODSTEP platform [19] Esprit III project GOODSTEP No 6115) concerns active rules for supporting reactive capabilities. The NAOS prototype has been developed for managing events produced by tools, i.e. 02 applications, and for executing Event Condition Action rules triggered by ....

F. Bancilhon, C. Delobel, and P. Kanellakis, editors. Building an Object-Oriented Database System - The Story of 02. Morgan Kaufmann, 1992.

....the set of superconcepts common to fc16 ,c17 ,c18 g, and Join(fc16 ,c17 ,c18 g) fc3g is the smallest common superconcept of fc16 ,c17 ,c18 g. 3 Object Modeling of Concept Lattices In this section, we consider the representation of concept lattices in the O 2 database system. We choose O 2 [4] because it is fully ODMG compliant [8] and in particular it is the rst system that supports the ODMG query language OQL which can easily be extended. The object database generic schema called O 2 Concept Generic Database Schema which is supported by the O 2 data model [14] is proposed. Concept ....

F. Bancilhon, C. Delobel, and P. Kanellakis, editors. Building an Object-Oriented Database System: The Story of O2 . Morgan Kaufmann, 1992.

....an example of a database schema together with an associated base. The O 2 Views data model is further presented with a motivating example of a view definition. We assume the reader to be familiar with object oriented related concepts. Readers interested in obtaining more details are referred to [BDK92] Data can be values (instances of types) or objects (instances of classes) Classes encapsulate data defined by an underlying class type (tuple type, the C like atomic types and the constructed types list, set and bag) together with methods which operate on the data. A class might inherit from ....

....and returns a result of type type expression. A query returns an object or a value. Returned objects are those existing in the root base. Returned values are atomic values or complex values constructed using type constructors (e.g. set,tuple) on existing values and objects. As described in [BDK92] OQL is a functional language. An OQL query is a function taking zero or many arguments. The query computing the value of a virtual attribute can be written as follows: va = f(ra 1 ; ran ) where each ra i is a root attribute and f is the OQL query defining va. Let us first consider the ....

F. Bancilhon, C. Delobel, and P. Kanellakis, editors. Building an Object-Oriented Database System --- The Story of O 2 . Morgan Kaufmann, San Mateo, California, 1992.

....data. We primarily present two languages, Stanford s Lorel [AQM 97] and University of Pennsylvania s UnQL [BDHS96] Lorel Lore is a pioneering project in semistructured data. Originally, the language Lorel (i.e. Lore language) was implemented on top of the object oriented DBMS O 2 [BDK92a] Now it has been rebuilt as a stand alone system. We describe Lorel in its re ned version called Lorel96 as presented in [AQM 97] The original language, now dubbed Lorel1, was presented in [QRS 95] Lorel was designed to be a query language for the Object Exchange Model OEM, but it can ....

F. Bancilhon, C. Delobel, and P. Kanellakis, editors. Building an ObjectOriented Database System: The Story of O 2 . Morgan Kaufmann, San Francisco, CA, USA, 1992.

....and (iii) free memory regularly. If new optimizations have to be added, they will be encoded in the search strategy and the code generation phase remains unchanged. The RelOO prototype generates programs that use the ODBC [Mic94] interface to query any relational database and load data to an O 2 [BDK92] database (because there is no standard interface to access object databases) Finally, our implementation and optimization techniques can be used very easily to load other kinds of data (see the discussion in Section 7) We are aware of several research efforts on efficient bulk loading of ....

F. Bancilhon, C. Delobel, and P. Kanellakis, editors. Building an Object-Oriented Database System --- The Story of O 2 . Morgan Kaufmann, San Mateo, California, 1992.

....views. The schema definition language furthermore consists of a language for the implementation of the methods and of query language. The method implementation language is a Turing complete procedural programming language which also can contain expressions of the query language like in O2 [BDK92]. Similar to [LS92] the query language offers generic operations for projection, selection, extension, join, and set operations. Without going into details we briefly present the semantics of these operations. Selection returns a set of objects which validate a selection predicate. Projection ....

F. Bancilhon, C.Delobel, P. Kanellakis (eds.): Building an Object-Oriented Database System - The Story of 0 2 .Morgan-Kaufmann, San Mateo, 1992.

....our model. An object is persistent, if it is a member in (at least) one class or if it is referenced by a persistent object. The language for the implementation of the methods is a Turing complete procedural programming language which also can contain expressions of the query language like in O 2 [3]. The query language offers generic operations for projection, selection extension, join and set operations, similar to [8] Query expressions may be object preserving, i.e. the objects of the result set have the same object identifiers as the original objects. They may be object generating, where ....

F. Bancilhon, C.Delobel, P. Kanellakis (eds.): Building an Object-Oriented Database System - The Story of 0 2 . Morgan-Kaufmann, San Mateo, 1992.

....relationships. Given this fact, it may be hard for potential users and even a CV s own designers to orient themselves to the vast content of a CV and exploit its many advantages. In previous work, we have devised a novel technique for modeling a CV as an object oriented database (OODB) [2, 3, 5, 12, 17, 21, 34], a form we call an Object Oriented Vocabulary Repository (OOVR) 19, 20] Using our methodology, we have constructed OOVRs based on the MED and the InterMED [25] Both OOVRs are up and running in ONTOS DB Explorer [26, 31] a commercial OODB management system. Access to the InterMED OOVR is ....

F. Bancilhon, C. Delobel, and P. Kanellakis, editors. Building an Object-Oriented Database System: The Story of O 2 . Morgan Kaufmann Publishers, Inc., San Mateo, CA, 1992.

....c A = In particular, inh S (c; A) c if A is a top level attribute of (c) This notion of inheritance strategy covers strategies (such as an ordering on classes) that are commonly used to resolve multiple inheritance in practice. Similarly, if we wish to use the strategy of the O 2 system [3] where renamed inheritance of the same attribute with distinct origins is desired, we could generalize inh S (c; A) to return all pairs (d; A 0 ) with classes d from which attribute A, renamed to A 0 , is inherited. Applying inh S on a POB schema S = C; me; induces another POB schema ....

F. Bancilhon, C. Delobel, and P. Kanellakis, editors. Building an Object-Oriented Database System: The Story of O 2 . Morgan Kaufmann, Los Altos (CA), 1991.

....with respect to updates etc. There exist several approaches to persistent object stores coping with the core of these problems, i.e. with data structures and efficient access methods. These approaches range from the physical storage component of a commercial object oriented database system [1] to various ongoing research investigations and prototypical systems. In general, the physical storage structure is assumed to consist of physical objects that are linked by directed physical references, i.e. we may simply think of a physical reference graph. This is close to the object model ....

....Since we may exploit well known relational access methods [3] for associative access and realize object driven access via the other ones, we shall concentrate only on navigational access. Existing approaches to forward or backward navigational access either use direct physical pointers as in [1], various index structures including nested indices, path indices and multi indices [2] the latter one based on the relational join indices [11] also implemented in the O 2 system [1] access support relations as in [4] which may be regarded as join indices over paths, specific physical ....

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F. Bancilhon, C. Delobel, P. Kanellakis (Eds.). Building an object oriented database system -- the story of O 2 . Morgan-Kaufmann Publishers. San Mateo 1992.

....data types and or the NF 2 (Non First Normal Form) relations. PostGres [15] is an example of a relational DBMS extended along the first axis and currently used for querying by image content [13] The object oriented approach gives rise to objectoriented DBMS (OODBMS) such as ORION [9] O 2 [4], etc. OODBMS are recognised for their adequate support of complex objects, a generalisation of NF 2 , which is typically the case of any multimedia object. Nevertheless, several problems are still to be resolved in order to present a complete multimedia DBMS (MDBMS) Firstly, new data models ....

Bancilhon, F., Delobel, C., Kannelakis, P. (eds.); Building an Object-Oriented Database System: The Story of O 2 ; MorganKaufmann, 1992

....(continuous) E 1 ,E 2 ) E 2 exclusive: E 1 E 2 exclusive: E 2 , E 3 , E n ) E n exclusive: Figure 10: The semantics of event expressions in Ode 4. 5 NAOS The rule model of NAOS has been implemented as a prototype on top of the O 2 object oriented database management system ([BaDK92]) Event type pattern NAOS ( CoCo96] provides the binary event operators conjunction ( disjunction ( strict disjunction ( s ) sequence ( and strict sequence ( and the unary operators negation ( iteration (n(E) and strict iteration (n. E) They are introduced on an informal ....

F. Bancilhon, C. Delobel, P. Kanellakis (Eds.): Building an Object-Oriented Database System - The story of O2. Morgan Kaufmann, 1996.

.... that the new SQL3 will also support that kind of extension [Melton Simon 93] The object oriented approach, through the combination of artificial intelligence and language theory advances [Stefik Bobrow 86] allowed the rise of object oriented DBMS (OODBMS) such as ORION [Kim et al. 90] O 2 [Bancilhon et al. 92] ONTOS, GemStone, Versant, Object Store, etc. Chorafas Steinmann 93] In particular, OODBMS are recognised for their adequate support of complex objects, a generalisation of NF 2 , which is typically the case of any multimedia object. But, several problems are still to be resolved in order ....

Bancilhon, F., Delobel, C., Kannelakis, P. (eds.); Building an ObjectOriented Database System: The Story of O 2 ; Morgan-Kaufmann, 1992

....(the tree structure being hidden in the value of the term) which renders the description model fully compatible with an object oriented database representation. 5 Implementation In this section we describe a prototype implementation of the DB with the object oriented database system (ODBMS) O 2 [22] and its querying with the OQL query language [15] Although perhaps too complex as an end user language, OQL supports rather complex queries and allows a powerful mediation with information sources. We look at two possible implementations of the DB. The first subsection describes an ....

Bancilhon Francois, Delobel Claude, and Kanellakis Paris. Building an Object-Oriented Database System : The Story of O2 . Morgan Kaufman, 1992.

....systems, but more often, in applications relying on external data that has to be refreshed regularly. Indeed, one finds more and more object replications of data that are used by satellite Java or C persistent applications. For example, we know that the O 2 database system from O 2 Technology [BDK92] is used in that manner on industrial databases supporting several gigas of data. The migration problem turns out to be extremely complicated. It is not rare to find migration programs requiring hours and even days to be processed. 1 Furthermore, efficiency is not the only aspect of the problem. ....

....very long processing. It is thus vital to integrate physical requirements in the actual migration. We consider two physical properties: clustering and ordering. Clustering techniques are provided by most object database systems with different approaches and have been studied intensively (e.g. BDK92, TN92] The goal of a cluster is to minimize page faults by placing objects that are often accessed together as close as possible on disk. In RelOO, we do not assume any particular system clustering policy. We provide a primitive to specify clusters and a rewriting mechanism that takes this ....

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F. Bancilhon, C. Delobel, and P. Kanellakis, editors. Building an Object-Oriented Database System --- The Story of O2 . Morgan Kaufmann, San Mateo, California, 1992.

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F. Bancilhon, C. Delobel, and P. Kanellakis (ed.), "Building an object-oriented database system: the story of O2", Morgan Kaufmann, San Mateo, California, 1992.

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Bancilhon, F., C. Delobel, and P. Kanellakis, eds. Building an ObjectOriented Database System : The Story of O2. 1992, Morgan Kaufmann.

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F. Bancilhon, C. Delobel, and P. Kanellakis. Building an Object-Oriented Database System: the Story of O2 . Morgan Kaufmann, 1992.

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F. Bancilhon, C. Delobel, and P. Kanellakis. Building an Object-Oriented Database System: The Story of O2. Morgan Kaufmann, 1992.

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