서지주요정보
다차원 화일구조의 물리적 설계기법 및 객체지향 데이타베이스 색인기법에의 응용 = A physical design method for multidimensional file organizations and its application to indexing in object-oriented databases
서명 / 저자 다차원 화일구조의 물리적 설계기법 및 객체지향 데이타베이스 색인기법에의 응용 = A physical design method for multidimensional file organizations and its application to indexing in object-oriented databases / 이종학.
저자명 이종학 ; Lee, Jong-Hak
발행사항 [대전 : 한국과학기술원, 1997].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8008224

소장위치/청구기호

학술문화관(문화관) 보존서고

DCS 97029

SMS전송

도서상태

이용가능

대출가능

반납예정일

등록번호

9005519

소장위치/청구기호

서울 학위논문 서가

DCS 97029 c. 2

SMS전송

도서상태

이용가능

대출가능

반납예정일

초록정보

This dissertation proposes indexing techniques using multidimensional file organizations for object-oriented databases. Since most conventional indexing techniques for object-oriented databases use a one-dimensional index structure such as the $B^{+}$-tree, they do not often handle complex queries involving both an attribute and the class hierarchy. Physical database design for multidimensional file organizations is defined as the problem of determining the region splitting strategy for constructing an optimal multidimensional file organization that minimizes the cost of processing a given query pattern. Recently, many multidimensional file organizations have been proposed in the literature. However, there has been no effort for their physical database design. In this dissertation, we first propose a physical database design methodology for the optimal configuration of multidimensional file organizations, and then propose a tunable two-dimensional class indexing technique for object-oriented databases applying this design methodology. We then propose a multidimensionally extended scheme of this indexing technique for indexing nested attributes. First, we show that the performance of query processing is highly affected by the similarity between the shapes of query regions and page regions in the domain space, and then propose a physical database design method for finding the optimal configuration of the multidimensional file by controlling the interval ratio of the page regions along different axes to achieve the similarity. For performance evaluation, we run extensive experiments with the multilevel grid file, a multidimensional file organization, using various types of queries and object distributions. The results indicate that our proposed method builds optimal multilevel grid files regardless of the query types and object distributions. When the interval ratio of a two-dimensional query region is 1:1024, the performance of the proposed method is enhanced by as much as 7.5 times over that of the conventional method that has the interval ratio of 1:1 employing the cyclic splitting strategy. The performance is further enhanced for the query types having higher interval ratios. Second, we propose a tunable two-dimensional class indexing technique applying the proposed physical database design methodology. We use two-dimensional file organizations as the index structure. This indexing technique deals with the problem of clustering objects in a two -dimensional domain space that consists of a key attribute domain and a class identifier domain. In conventional class indexing techniques using one- dimensional index structures such as the $B^{+}$-tree, the clustering property is exclusively owned by one attribute. Such one-dimensional structures can be classified into two categories by the way they choose the clustering domain. One is key clustering indexing that clusters objects according to their key values, and the other class clustering indexing that clusters objects according to their class identifiers. These indexing techniques do not handle efficiently the queries that address both the attribute keys and the class identifiers. Our proposed tunable two-dimensional class indexing technique enhances query performance by adjusting the degree of clustering between the key value domain and the class identifier domain based on precollected usage pattern about the queries. For performance evaluation, we first compare our tunable two-dimensional class indexing with the conventional key clustering indexing and the class clustering indexing as a cost model. We then verify the cost model through experiments using the multilevel grid file as the two-dimensional index, and show that our proposed method indeed builds optimal class index structures regardless of the query types and object distributions. Third, we also propose an extended scheme of the tunable two-dimensional class indexing technique for indexing the nested attribute in object-oriented databases. In this scheme, we construct indexes using multidimensional file organizations that include one class identifier domain per class hierarchy on a path expression that defines the indexed nested attribute. This scheme supports efficiently queries that involve search conditions on the nested attribute represented by an extended path expression. An extended path expression is a one in which a class hierarchy can be substituted by an individual class or a subclass hierarchy in the hierarchy.

서지기타정보

서지기타정보
청구기호 {DCS 97029
형태사항 x, 132 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Jong-Hak Lee
지도교수의 한글표기 : 황규영
지도교수의 영문표기 : Kyu-Young Whang
수록잡지명 : "A Physical database design method for multidimensional file organizations". Information Siences. Elsevier science Inc.
학위논문 학위논문(박사) - 한국과학기술원 : 전산학과,
서지주기 참고문헌 : p. 122-132
주제 다차원 화일구조
물리적 데이타베이스 설계
질의처리
클래스 계층 색인
중포속성 색인
Multidimensional file organizations
Physical database design
Query processing
Class hierarchy index
Nested attribute index
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