• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2273-2286
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• 2000

In order to acquire the precise and fast response for an analytical query, proper selection of the views to materialize in data warehouse is very crucial. In traditional view selection algorithms, the whole relations are considered to be selected as materialized views. However, materializing the whole relations rather than a part of relations results in much worse performance in terms of time and space cost. Therefore, we present an improved algorithm for selection of views to materialize using clustering method to overcome the problem resulted from conventional view selection algorithms. In the presented algorithm, ASVMRT(Algorithm for Selection of Views to daterialize using Iteduced Table). we first generate reduced tables in clata warehouse using automatic clustering based on attrihute-values density, then we consider the combination of reduced tables as materialized views instead of the combination of the original hase relations. For the justification of the proposecl algorithm. we show the experimental results in which both time and space cost are approximately 1.8 times better than the conventional algorithms.

• Journal of KIISE:Databases
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• v.28 no.4
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• pp.587-595
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• 2001

Precomputation and materialization of parts. commonly called views of a data cube is a common technique in data warehouses The view is defined as the result of a query which is defined through aggregate functions In this paper we introduce the concept of fine granule view. The fine granule view is the result of a query defined through aggregate functions and the range on each dimension, where the subdivision of each dimension is based on queries access patterns. For the representation and selection of fine granule views to materialize, we define the ANO-OR cube graph and AND-OR minimum cost graph. With these structures, we propose a fine granule view materialization method. And through experiments, we evaluate the performance of the proposed method.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10c
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• pp.262-264
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• 2002

데이터웨어하우스는 대용량의 데이터를 대상으로 복잡한 분석을 수행하거나 전략적 의사 결정을 위해 사용되기 때문에 신속한 질의 응답을 위한 성능 관리가 무엇보다 중요하다. 데이터웨어하우스는 일반 운영계 시스템과는 다른 목적과 특성을 가지기 때문에 그에 적합한 성능 모니터링 방법이 필요하다. 본 연구에서는 오라클 데이터베이스를 위한 OLTP(On-Line Transaction Processing)용 국산 성능 모니터링 도구인 DBMax를 데이터웨어하우스 환경에 적용할 수 있도록 기능을 확장한다. 우선 기존의 운영계 시스템과는 구분되는 데이터웨어하우스의 특성을 토대로 오라클9i에서 제공하고 있는 성능 항상 기법인 실체화된 뷰(MV: Materialized View)와 EH(Data Extraction, Transformation and Loading) 화장 기능을 모니터링하기 위한 요구사항을 분석하고 이를 지원하기 위한 DBMax 확장 방안을 설계 및 구현한다. 실체화된 뷰와 ETL 확장 기능을 위해 제공되는 오라클9i의 다양한 스키마 객체에 대한 정보 및 성능 관련 지표를 제시하여 SQL 튜닝 기능을 지원하며 사후 분석을 위한 DBMax의 로그 파일에서 의미 있는 SQL문을 추출하여 잠재적으로 유용한 실체화된 뷰를 권고할 수 있도록 기능을 확장한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.04a
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• pp.28-35
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• 2000

In order to acquire the precise and fast response for an analytical query, proper selection of the views to materialize in data warehouse is very crucial. In traditional algorithms, the whole relation is considered to be selected as materialized views. However, materializing the whole relation rather than a part of relation results in much worse performance in terms of time and space cost. Therefore, we present a new algorithm for selection of views to materialize using clustering method in order to improve the performance of data warehouse including this problem. In the presented algorithm, ASVMR(Algorithm for Selection of Views to Materialize using Reduced table), we first generate reduced tables in data warehouse using automatic clustering based on attribute-values density, then we consider the combination of reduced tables as materialized views instead of the combination of the original base relations. We also show the experimental results in which both time and space cost are approximately 1.8 times better than the conventional algorithms.

• Journal of the Korea Society of Computer and Information
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• v.4 no.4
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• pp.69-76
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• 1999

Recently, it has been studied the methods to materialize and precompute the query results for complexed spatial aggregation queries with high response time and the popular use in spatial data warehouse. In this paper, we propose extended selective materialization algorithm and present the way to materialize selectively which is considered access frequency and computation time of spatial operation according to spatial measures of spatial views for improvement of existing selective materialization algorithms.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2418-2423
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• 2012

A smart phone which is one of the new IT technologies can be viable on various enterprise applications since it provides easily information and services. Especially, a smart phone can request queries to a server which finds massive data for decision making and receive the results of the queries from the server. However, a smart phone has a drawback that its battery is consumed easily due to the 4G communication. In this paper, we propose mobile views in order to reduce the easy consumption of a battery on mobile client-server environment. The proposed mobile view scheme reduces the number of communication which is leading to power consumption using materialized views for processing queries. We also classify the methods to control the consistency of the mobile view as the sources of the view are changed and present the cost of each method based on the cost model of battery consumption.

• Journal of Internet Computing and Services
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• v.10 no.2
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• pp.99-116
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• 2009

For the mapping of two dimensional table structures of relational databases to the hierarchical XML documents, we apply the foreign key relationships of relational databases. In other words, the primary key of another table referenced by a foreign key of one tuple is mapped to the parent of the foreign key. Then XML hierarchies with order are expressed. In addition, the XML view file generated by the foreign key mappings shows side effects in the case of the relational database update for the satisfaction of referential integrity constraint in the foreign key. Thus, by inferring the foreign key roles at the generation of XML hierarchies, we can anticipate where the side effects occur in the hierarchies. We keep the XML view files up-to-date by reflecting the side effects to the XML files at the update of the underlying relational databases.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.174-177
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• 2012

최근 정보 기술의 가장 큰 변화 중 하나인 스마트폰은 다양한 정보 및 서비스를 손쉽게 제공하므로 기업의 여러 분야에 활용될 수 있다. 특히 의사결정을 위해 구축된 방대한 데이터를 검색하는 시스템의 경우에 스마트폰으로 서버에 질의를 요청하여 결과를 제공받을 수 있다. 스마트폰의 경우 4G 방식을 사용하여 빠른 속도로 통신할 수 있으나 배터리 소모가 매우 심하다는 것이 큰 단점이다. 본 논문에서는 모바일기기인 클라이언트와 서버로 구성된 모바일환경에서 배터리의 소모를 줄이기 위해 모바일 뷰를 제안한다. 모바일 뷰는 질의처리 시 실체화 뷰를 이용하여 서버와의 통신을 줄임으로써 배터리 소모를 줄인다. 또한 소스 변경에 따라 모바일 뷰의 일관성을 제어하기 위한 방법을 분류하고 제시된 배터리소모 비용 모델을 기반으로 각 방법의 비용을 제시한다.

• Proceedings of the Korea Contents Association Conference
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• 2015.05a
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• pp.47-48
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• 2015

본 논문에서는 의사 분산 트리를 이용하여 효율적으로 후보 실체 뷰를 선택하는 기법을 제안한다. 제안하는 기법은 후보 실체 뷰의 이득, 실체화 크기, 그리고 갱신율을 고려하여 의사 결정 트리로 구축한다. 의사 결정 트리를 이용하여 효율이 높은 후보 실체 뷰의 선택 및 빠른 교체 수행을 목적으로 한다.

• The Journal of the Korea Contents Association
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• v.8 no.1
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• pp.290-299
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• 2008

We propose the query optimization technique using query classification in hybrid spatial DBMS. In our approach, user queries should to be classified into three types: memory query, disk query, and hybrid query. Specialty, In the hybrid query processing, the query predicate is divided by comparison between materialized view creating conditions and user query conditions. Then, the deductions of the classified queries' cost formula are used for the query optimization. The optimization is mainly done by the selection algorithm of the smallest cost data access path. Our approach improves the performance of hybrid spatial DBMS than traditional disk-based DBMS by $20%{\sim}50%$.