• The Journal of Information Technology and Database
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• v.1 no.1
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• pp.9-30
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• 1994

The objective of this paper is to give a brief review of relational design methodology, and show how a relational schema can be converted into an object-relational schema. We first introduce relational terminology and describe the relational design process along with its limitations. Next we show how the relational model can be extended to overcome these limitations : these extensions form the core of an object-relational data model ; we use the UniSQL/X data model as an example. We illustrate the process or converting a relational schema into an object-relational schema, and show the benefits of this conversion with respect to queries. The conversion process is then summarized as a set of guidelines. Finally, we make our conclusions.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.31B no.9
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• pp.10-21
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• 1994

Query-by-Example(QBE) is high-level display-oriented databased manipulation language that provides a convenient and unified style for querying, updating, defining, and controling a relational database. QBE is relationally complete. However, lack of aubquery constructs limits th usability of QBE significantly. In particular, certain queries cannot be represented in one window. In this paper, we define a subquery box and extend QBE for subquery construction. The Extended QBE makes it possible to represent the queries that the QBE cannot do in one window, reducing the overhead and complexity of composing those queries. We also define the grammar of the Extended QBE and present the parsing techniques. Finally, we present an algorithm to transform the queries in Exteded QBE to those in SQL. The result of the transformation can be executed using dynamic SQL features of any SQL system. The proposed language has been implemented on OS/2 using the OS/2 EE Database Manager.

• Journal of the Korea Society of Computer and Information
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• v.23 no.3
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• pp.49-54
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• 2018

A data warehouse is a system that collectively manages and integrates data of a company. And provides the basis for decision making for management strategy. Nowadays, analysis data volumes are reaching critical size challenging traditional data ware housing approaches. Current implemented solutions are mainly based on relational database that are no longer adapted to these data volume. NoSQL solutions allow us to consider new approaches for data warehousing, especially from the multidimensional data management point of view. In this paper, we extend the data warehouse design methodology based on relational database using star schema, and have developed a consistent design methodology from information requirement analysis to data warehouse construction for large scale data warehouse construction based on MongoDB, one of NoSQL.

• The Journal of Information Technology and Database
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• v.3 no.1
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• pp.65-84
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• 1996

대규모 멀티미디어 데이타베이스 서비스 시스템은 웹(Web)의 대규모 멀티미디어 정보 서비스의 우수성과 데이타베이스 시스템의 방대한 데이타베이스 관리 가능을 상호 보완적으로 통합함으로써 구현할 수 있다. 데이타베이스 통로(gateway)는 이러한 통합의 핵심적인 소프트웨어라 할 수 있다. 데이타베이스 통로의 필요성이 인식된 후로 현재 많은 상용 및 연구용 제품이 개발되어 왔다. 데이타베이스 통로의 구조는 데이타베이스 접속을 웹에 어떻게 연동시키는가에 따라 다양하게 나누어지고 구조에 따라 성능도 달라지게 된다. 본 논문에서는 여러가지 데이타베이스 통로의 구조에 대하여 분류체계를 제안하고, 현재 충남대학교에서 개발하고 있는 UniWeb의 설계 및 구현을 기술한다. UniWeb은 웹을 위한 UniSQL/X 데이타베이스 통로로서 DBMS의 최적화 가능을 최대한 활용할 수 있는 구조를 가지고 있으며, 웹 응용 개발을 위한 환경을 지원하고 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.406-408
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• 2004

To develop enterprise architecture based distributed application needs consideration of various factors such as division of role between web-designer and software developer, defining entity and its usage, database connection and transaction processing. This paper presents DONSL(Data Server of Non SQL-Query) architecture that provides solution to above aspects through web-tier object modeling guaranteeing efficient transaction processing and performance between web-tier and 08MS through simplified usage of query logic property.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.295-297
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• 2001

데이터베이스의 성능개선을 위해서 여러 가지 튜닝기법을 사용하고 있다. 그러나 DBMS의성능문제는 약 60%가 응용프로그램의 SQL문에서 발생한다. 따라서 본 연구에서는 여러 가지 상황 중 MS SQL Server 2000의 [SQL Query Analyzer]를 사용하여 동일 쿼리의 셀프조인과 외부조인의 실험을 통하여 수행성능을 평가하였다.

• Spatial Information Research
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• v.13 no.3 s.34
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• pp.221-237
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• 2005

This study attempts at building a GIS computing environment that incorporates object-relational spatio-temporal database for the time geography model with space-time path, space-time prism and space-time accessibility. The proposed computing environment is composed of ( i ) mobile GIS application for collecting spatio-temporal trajectory data of an individual, ( ii ) spatio-temporal database server that includes time geography model, and (iii) geovisualization client that performs time geographic queries to the spatio-temporal database. The spatio-temporal trajectory data collected by GPS-PDA client is automatically processed and sent to server through data management middleware. The spatio-temporal database implemented by extending a generic DBMS provides spatio-temporal objects, functions, and SQL. The geovisualization client illustrates 3D visual results of the queries about space-time path, space-time prism, and space-time accessibility. This study confirms the possibility of integrating mobile GIS and DBMS for time geography model, and it presents the appropriate database model with spatio-temporal objects and functions that may handle very large data for time geography application.

• Journal of the Korea Society of Computer and Information
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• v.25 no.4
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• pp.123-131
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• 2020

The pattern query in graph database has advantages of easy query expression and high query processing performance compared to relational database SQL. However, unlike the relational database, the graph database may not utilize the advantages of pattern query depending on modeling because the methodology for building the logical data model is not defined. In this study, in the is-a node modeling method that appears during the graph modeling process, we experiment that there is a difference in performance between graph pattern query when designing with a generalization model and designing with a specialization model. As a result of the experiment, it was shown that better performance can be obtained when the is-a node is designed as a specialization model. In addition, when writing a pattern query, we show that if a variable is bound to a node or edge, performance may be better than that of the variable of not bounded. The experimental results can be presented as an is-a node modeling method for pattern query and a graph query writing method in the graph database.

• Journal of the Korea Society of Computer and Information
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• v.23 no.3
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• pp.41-48
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• 2018

The recent sudden increase of big data has characteristics such as continuous generation of data, large amount, and unstructured format. The existing relational database technologies are inadequate to handle such big data due to the limited processing speed and the significant storage expansion cost. Current implemented solutions are mainly based on relational database that are no longer adapted to these data volume. NoSQL solutions allow us to consider new approaches for data warehousing, especially from the multidimensional data management point of view. In this paper, we develop and propose the integrated design methodology based on MongoDB for big data applications. The proposed methodology is more scalable than the existing methodology, so it is easy to handle big data.

• Proceedings of the Korean Information Science Society Conference
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• 2002.04b
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• pp.121-123
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• 2002

본 논문에서는 주기억 데이터베이스 시스템을 위만 질의처리 엔진의 설계 및 구현에 대해서 설명하였다. 이를 바탕으로 Embedded SQL 지원을 위한 Pre-compiler 구현 방법 , 단순 질의 및 Join 과정에서의 주기억 장치의 효율적인 사용 방법 , Cursor, Dynamic SQL 처리 방법에 대해 소개하였다.