OLEYNIK PAVEL P. · RePEc: Research Papers in Economics
Modern corporate information systems (CIS) are designed by employing object-oriented paradigm and concepts. This approach is often applied both to implement client applications and to build a server component (target DBMS). The application of object-oriented design pattern in software development enables to save business objects from RAM to persistent memory. This paper focuses on XOQL (XML Object Query Language) - an object query language that uses XML to describe syntax. This article presents a deep and comprehensive review of existing publications. Abundance of examples enables to demonstrate various currently available languages. This paper suggests a feasible option to present basic syntactic constructions of object query language in the form of XML-documents. Prior to syntax design the optimality criteria have been formulated (these are described in detail in this paper). Query language syntax extensions are outlined in addition to basic ones, as well as extension approaches by involving proprietary constructions. An optimal language structure is presented accompanied by descriptions of tags, attributes and admissible values. At the end of this article there are plenty of examples of various common queries.
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2014
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Mohamed Elfeky, Amani Saad, Souheir Fouad · 2000
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Jibin Zhan · Summit (Simon Fraser University) · 1994
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Praveen Gutti · UKnowledge (University of Kentucky) · 2007
This work presents SPOQL, a structured query language for Semistructured Probabilistic Object (SPO) model [4]. The original query language for semistructured probabilistic database management system [20], SP-Algebra [4], has limitations such as complex functional notation and unfamiliarity to application programmers. SPOQL alleviates these problems by providing a user friendly and familiar SQL-like declarative syntax for writing queries against SPDBMS. We show that parsing SPOQL queries is a more involving task than parsing SQL queries. We describe the evaluation algorithm for SPOQL queries that we have implemented.
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V. M. Dimitrov · PROGRAMMNAYA INGENERIA · 2017
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V. M. Dimitrov, A. V. Voronin, Iu. A. Bogoiavlenskii · PROGRAMMNAYA INGENERIA · 2017
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Serge Abiteboul, Paris C. Kanellakis · Journal of the ACM · 1998
We demonstrate the power of object identities (oids) as a database query language primitive. We develop an object-based data model, whose structural part generalizes most of the known complex-object data models: cyclicity is allowed in both its schemas and instances. Our main contribution is the operational part of the data model, the query language IQL, which uses oids for three critical purposes: (1) to represent data-structures with sharing and cycles, (2) to manipulate sets, and (3) to express any computable database query. IQL can be type checked, can be evaluated bottom-up, and naturally generalizes most popular rule-based languages. The model can also be extended to incorporate type inheritance, without changes to IQL. Finally, we investigate an analogous value-based data model, whose structural part is founded on regular infinte trees and whose operational part is IQL.
Cited by 66Open access
Abiteboul, Serge, Kanellakis, P.C. · HAL (Le Centre pour la Communication Scientifique Directe) · 1989
Résumé disponible dans les fichiers attachés
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Kirby McMaster, Samuel Sambasivam, Brian Rague · Informing Science and IT Education Conference · 2013
An international association advancing the multidisciplinary study of informing systems. Founded in 1998, the Informing Science Institute (ISI) is a global community of academics shaping the future of informing science.
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Serge Abiteboul, Paris C. Kanellakis · ACM SIGMOD Record · 1989
We demonstrate the power of object identities (oid's) as a database query language primitive. We develop an object-based data model, whose structural part generalizes most of the known complex-object data models: cyclicity is allowed in both its schemas and instances. Our main contribution is the operational part of the data model, the query language IQL, which uses oid's for three critical purposes: (1) to represent data-structures with sharing and cycles, (2) to manipulate sets and (3) to express any computable database query. IQL can be statically type checked, can be evaluated bottom-up and naturally generalizes most popular rule-based database languages. The model can also be extended to incorporate type inheritance, without changes to IQL. Finally, we investigate an analogous value-based data model, whose structural part is founded on regular infinite trees and whose operational part is IQL.
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F. Connan, Daniel Rocacher · 2002
Fuzzy querying systems allow queries to be more or less satisfied. Then, the results of a query are ranked according to their degree of satisfaction. The need for fuzzy querying systems has increased since the arrival of multimedia data in the field of database management systems. In fact, queries on multimedia data are often an imprecise description of their content; therefore, queries should not be interpreted strictly. To model fuzzy querying in a multimedia database, we propose the definition of a fuzzy querying system based on fuzzy logic and applied in an object-oriented environment. In this way, we define new data types, such as fuzzy collections and fuzzy predicates, and we also define extensions of classic object-oriented retrieval operators, such as the operators of AQUA (A QUery Algebra) and OQL (Object Query Language). The objective of our work is to define a general framework on which applications can fully exploit the graduality associated with their processing tools.
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Emil Wcisło, Piotr Habela, Kazimierz Subieta · Communications in computer and information science · 2011
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Damir Bećarević · Arrow@dit (Dublin Institute of Technology) · 2004
The Fischlar system provides a large centralised repository of multimedia files. As expansion is difficult in centralised systems and as different user groups have a requirement to define their own schemas, the EGTV (Efficient Global Transactions for Video) project was established to examine how the distribution of this database could be managed. The federated database approach is advocated where global schema is designed in a top-down approach, while all multimedia and textual data is stored in object-oriented (O-O) and object-relational (0-R) compliant databases. \n \nThis thesis investigates queries and updates on large multimedia collections organised in the database federation. The goal of this research is to provide a generic query language capable of interrogating global and local multimedia database schemas. Therefore, a new query language EQL is defined to facilitate the querying of object-oriented and objectrelational database schemas in a database and platform independent manner, and acts as a canonical language for database federations. A new canonical language was required as the existing query language standards (SQL: 1999 and OQL) axe generally incompatible and translation between them is not trivial. EQL is supported with a formally defined object algebra and specified semantics for query evaluation. \n \nThe ability to capture and store metadata of multiple database schemas is essential when constructing and querying a federated schema. Therefore we also present a new platform independent metamodel for specifying multimedia schemas stored in both object-oriented and object-relational databases. This metadata information is later used for the construction of a global schemas, and during the evaluation of local and global queries. \n \nAnother important feature of any federated system is the ability to unambiguously define database schemas. The schema definition language for an EGTV database federation must be capable of specifying both object-oriented and object-relational schemas in the database independent format. As XML represents a standard for encoding and distributing data across various platforms, a language based upon XML has been developed as a part of our research. The ODLx (Object Definition Language XML) language specifies a set of XMLbased structures for defining complex database schemas capable of representing different multimedia types. The language is fully integrated with the EGTV metamodel through which ODLx schemas can be mapped to 0-0 and 0-R databases.
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D.K.C. Chan · Enlighten: Theses (The University of Glasgow) · 1994
This thesis proposes an object-oriented query language that is more powerful than many existing query languages. The language is formally specified and its expressive power is demonstrated by giving four translation schemes from other prominent object-oriented query languages. Further, this query language can be supported by a query algebra and both the query language and query algebra can be optimised using meaning preserving transformation rules. Object-Oriented Query Languages. The functional requirements of high-level object-oriented query languages are identified and they combine as well as supplement features found in existing object-oriented query languages. Effectively they formulate a query model against which existing query languages can be evaluated and compared. An evaluation of four representative query languages chosen from research prototypes and commercial products shows that none satisfies all the requirements. On the basis of the requirements a new query language, object comprehensions, is developed to provide a concise, clear, powerful, and optimisable query language for object-oriented databases. Some optimisation opportunities for the novel features are identified. A set of translation schemes from the query languages studied to object comprehensions is presented. Such translations demonstrate that object comprehensions are at least as powerful as these query languages and a system supporting object comprehensions can potentially support multiple query languages by providing translations to object comprehensions. Algebraic Support. The canonical algebra provides an abstract execution engine with which object comprehension queries can be expressed using algebraic operations. The translation scheme from object comprehensions to the canonical algebra is very simple and is no for supporting queries involving mixed collection classes The canonical algebra shares many operations with other query algebras and is formally specified. A set of transformation rules that can be used for optimisation is presented whose validity can be verified given the formal specification. Formal Data Model. The data model which forms the basis of investigation is formally defined using the specification language Z. This reference data model captures all the essential features of existing object-oriented data models including multiple inheritance. However, unlike existing data models, it also supports a generalised form of method over-loading. Static type checking of such overloaded methods is studied in this thesis.
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Serge Abiteboul, Paris C. Kanellakis · 1989
We demonstrate the power of object identities (oid's) as a database query language primitive. We develop an object-based data model, whose structural part generalizes most of the known complex-object data models: cyclicity is allowed in both its schemas and instances. Our main contribution is the operational part of the data model, the query language IQL, which uses oid's for three critical purposes: (1) to represent data-structures with sharing and cycles, (2) to manipulate sets and (3) to express any computable database query. IQL can be statically type checked, can be evaluated bottom-up and naturally generalizes most popular rule-based database languages. The model can also be extended to incorporate type inheritance, without changes to IQL. Finally, we investigate an analogous value-based data model, whose structural part is founded on regular infinite trees and whose operational part is IQL.
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D. N. Gavrilin, I. A. Kustova, Andrei Mantsivoda · The Bulletin of Irkutsk State University Series Mathematics · 2022
We are designing an application development technology based on an extended object-oriented approach, in which object models are enriched to the functionality of microservices. This variation is called microservice object-oriented programming. An object model as a microservice is an autonomous information system that behaves as a persistent storage and interacts with other models and external actors through the API. Moreover, understanding object models as microservices provides a fundamentally new low-code technology based on model visualization. This paper presents a query language for object models that works efficiently with persistent models. It is a subset of the Libretto language. The logical semantics of the language is described, as well as the method of compiling it into SQL, based on the use of an intermediate relational language. A SQL query language compiler has been implemented within the Ontobox platform. It shows high efficiency and is now actively used in real-life application development tasks solving.
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Piotr Cybula, Kazimierz Subieta · Lecture notes in computer science · 2009
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Manoj Chavda Department, Manoj Chavda, Peter T. Wood · 1997
We describe the design, implementation and user evaluation of QUIVER, a graph-based visual query language for object databases. The design goals of QUIVER include compliance to standards, comprehensive representational power, and consistency of visual representation. Compliance to standards is achieved through QUIVER queries being translated to OQL, the standard query language proposed by the Object Data Management Group (ODMG). Comprehensive representational power is gained by QUIVER supporting a significant number of object database constructs, including objects, literals, attributes, relationships, structures, collections, operations, (aggregate) functions, and subqueries. Consistency of visual representation is pursued by assigning similar visual representations to constructs with similar functionality, as well as by minimising the use of text in QUIVER queries. The language is implemented as a visual front-end to the O 2 object database system. Results of a user evaluation suggest...
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Emil Wcisło, Piotr Habela, Kazimierz Subieta · Lecture notes in computer science · 2012
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