• Title/Summary/Keyword: fact table

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A Nonunique Composite Foreign Key-Based Approach to Fact Table Modeling and MDX Query Composing (비유일 외래키 조합 복합키 기반의 사실테이블 모델링과 MDX 쿼리문 작성법)

  • Yu, Han-Ju;Lee, Duck-Sung;Choi, In-Soo
    • KSCI Review
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    • v.14 no.2
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    • pp.185-197
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    • 2006
  • A star schema consists of a central fact table, which is surrounded by one or more dimension tables. Each row int the fact table contains a multi-part primary key(or a composite foreign key) along with one or more columns containing various facts about the data stored in the row Each of the composit foreign key components is related to a dimensional table. The combination of keys in the fact table creates a composite foreign key that is unique to the fact table record. The composite foreign key, however, is rarely unique to the fact table record in real-world applications, particularly in financial applications. In order to make the composite foreign key be the determinant in real-world application, some precalculation might be performed in the SQL relational database, and cached in the OLAP database. However, there are many drawbacks to this approach. In some cases, this approach might give users the wrong results. In this paper, an approach to fact table modeling and related MDX query composing, which can be used in real-world applications without performing any precalculation and gives users the correct results, is proposed.

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A Nonunique Composite Foreign Key-Based Approach to Fact Table Modeling and MDX Query Composing (비유일 외래키 조합 복합키 기반의 사실테이블 모델링과 MDX 쿼리문 작성법)

  • Yu, Han-Ju;Lee, Duck-Sung;Choi, In-Soo
    • Journal of the Korea Society of Computer and Information
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    • v.12 no.1 s.45
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    • pp.177-188
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    • 2007
  • A star schema consists of a central fact table, which is surrounded by one or more dimension tables. Each row in the fact table contains a multi-part primary key(or a composite foreign key) along with one or more columns containing various facts about the data stored in the row. Each of the composit foreign key components is related to a dimensional table. The combination of keys in the fact table creates a composite foreign key that is unique to the fact table record. The composite foreign key, however, is rarely unique to the fact table retold in real-world applications, particularly in financial applications. In order to make the composite foreign key be the determinant in real-world application, some precalculation might be performed in the SQL relational database, and cached in the OLAP database. However, there are many drawbacks to this approach. In some cases, this approach might give users the wrong results. In this paper, an approach to fact table modeling and related MDX query composing, which can be used in real-world applications without performing any precalculation and gives users the correct results, is proposed.

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THE CLASSIFICATION OF A CLASS OF HOMOGENEOUS INTEGRAL TABLE ALGEBRAS OF DEGREE FIVE

  • Barghi, A.Rahnamai
    • Journal of applied mathematics & informatics
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    • v.8 no.1
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    • pp.71-80
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    • 2001
  • The purpose of this paper is to give the classification of homogeneous integral table algebras of degree 5 containing a faithful real element of which 2. In fact, these algebras are classified to exact isomorphism, that is the sets of structure constants which arise from the given basis are completely determined. This is work towards classifying homogeneous integral table algebras of degree 5. AMS Mathematics Subject Classification : 20C05, 20C99.

The Cultural History of Western Dining Atmosphere Display - Focusing on the structural elements of Table Decoration - (서양 식공간의 문화사적 고찰 - 테이블 데코레이션의 구성요소 중심으로 -)

  • Han, Kyung-Soo;Lee, U-Joo
    • Journal of the Korean Society of Food Culture
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    • v.19 no.1
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    • pp.12-29
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    • 2004
  • This paper tried to identify recognition and historical background about western table decoration. For the study, the documentary study would be accomplished. the range of time was during Renaissance, Baroque, Rococo, and Neo-classic period, and the range of space was among Italy, France, and England. Styles for example architectures, interior designs, arts, and sculptures represented their own period, and had great influences on eating habits, and the eating habits would be influent on kitchen utensils. As a results of the fact, the structural elements and decoration of table would be showed different characteristics according to periods of time. Today's food cultural trends consisted of consumption, taste, sense, and consumers' demands become diversified, so the paper would be an important data to understand new designs proper for our own modem sense that cope with modem feeling.

A STUDY OF SOME TESTS OF TREND IN CONTINGENCY TABLES

  • Jee, Eun-Sook
    • The Pure and Applied Mathematics
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    • v.4 no.1
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    • pp.7-18
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    • 1997
  • Consider an $r\;\times\;c$ contingency table under the full multinomial model in which each classification is ordered. The problem is to test the null hypothesis of independence. A number of tests have been proposed for this problem. In this article we show that all of these tests can be improved on in some sense for most cases. In fact the preceding tests sometimes are inadmissible in a strict sense. Furthermore, we show by example that in some cases improved tests can yield substantially improved power functions.

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DDC 지역구분표의 변천과정

  • 이창수
    • Journal of Korean Library and Information Science Society
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    • v.18
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    • pp.193-216
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    • 1991
  • The purpose of this study is to analyze the area table of twenty editions of the DDC in order to identify what major changes have been made chronologically. The summaries about which were discussed according to the edition order about the change processes of the most extensive area table of the DDC auxiliary table are as follows. 1. It is from the 17th edition that area table appeared as a special auxiliary table in DDC for the first time and the method of classifying areas like from 930 to 999 which is regional history in history class was taken before the introduction of independent area table. 2. The entry numbers in which the area table was applied increased continuously until the 18th edition but the applied entry number was rather decreased in the 20th edition especially the number was mainly decreased in history class, this is the result of the fact that the entry was classified by area table without enumerating each regional history in history class except for the basic area since the 17th edition but recently at least the area of over national unit according to the necessity of enumerating the entry in regional history within history class. 3. The relocation or revision of area table was made according to the literary warrant of the relevant area by period political and administrative conditions and the request of related organization or classifiers of the area rather than by the topographical features therefore the revision was made chiefly about the highly interested Europe Northern America especially the United States. 4. The entry numbers which were expanded according to area indicate that gradual improvement for the international feature as the revision of edition is repeated is made but because of the expansion of Northern America, especially the United States, regional disproportion is represented by the occupation of 56% in the entire entry numbers of the United States in case of the 20th edition. Lastly, the reasonable reform plans of area table will have to be groped on the basis of the results of analysis above and the consideration about the problems in the development of area table of DDC and the other main classification systems.

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Efficient Processin of Queries with Joints and Aggregate Functions in ROLAP Data Warehousing Environment (관계형 OLAP 데이터 웨어하우징 환경에서 조인과 집계함수를 포함하는 질의의 효율적인 처리)

  • Kim, Jin-Ho;Kim, Yun-Ho;Kim, Sang-Wook
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.39 no.5
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    • pp.1-10
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    • 2002
  • Efficient processing of expensive queries that include joins and/or aggregate functions is crucial in data warehousing environment since there reside enormous volume of data. In this paper, we propose a new method for processing of queries that have both of joins and aggregate functions. The proposed method first performs grouping of the dimension table and then processes join by using the bitmap join index. This makes only the fact table accessed for processing aggregate functions, and thus resolves the serious performance degradation of the existing method. For showing the superiority of the proposed method, we suggest the cost models for the proposed and existing ones, and perform extensive simulations based on the TPC-H benchmark.

Application of numerical models to determine wind uplift ratings of roofs

  • Baskaran, A.;Borujerdi, J.
    • Wind and Structures
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    • v.4 no.3
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    • pp.213-226
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    • 2001
  • Wind uplift rating of roofing systems is based on standardised test methods. Roof specimens are placed in an apparatus with specified table size (length and width) then subjected to the required wind load cycle. Currently, there is no consensus on the table size to be used by these testing protocols in spite of the fact that a table size plays a significant role in evaluating the performance. This paper presents a study with the objective to investigate the impact of table size on the performance of roofing systems. To achieve this purpose, extensive numerical experiments using the finite element method have been conducted to investigate the performance of roofing systems subjected to wind uplift pressures. Numerical results were compared with results obtained from experimental work to benchmark the numerical modeling. Required table size and curves for the determinations of appropriate correction factors are suggested. This has been completed for various test configurations with thermoplastic waterproofing membranes. Development of correction factors for assemblies with thermoset and modified bituminous membranes are in progress. Generalization of the correction factors and its usage for wind uplift rating of roofs will be the focus of a future paper.

Nitrogen changes during the development of eggs of melanoplus bivittatus (Melanoplus bivittatus 알 발생과정에 있어서의 질소의 소장)

  • Lee, Chul-Joon
    • Korean Journal of Microbiology
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    • v.1 no.1
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    • pp.19-25
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    • 1963
  • The studies could be summarized as follows: 1. Standard Rf Values were made as Table II for the identification of amino acids. 2. Amounts of free amino nitrogen in eggs were increased about 0.03% (Table IV) while the amounts of total nitrogen (Table III) were increased lower percentage during the ten days of development. 3. Three unknown substances were found newly during the development. 4. Eight ninhydrine positive amino acids were present, in the fresh embryonic eggs, but the numbers increased to eighteen after fifty days of development. 5. Through the development, there were large amounts of glutamic acid, aspartic acid and alanine. 6. After fifty days development, the amount of amides, such as asparagine, glutamine and alanine were increased very large which were very small amount before it and the amount of asparagine were more than that of glutamine. 7. Tryptophane, Cystine , Histidine were detected after 50 days of development. This is very remarkable fact.

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MLPPI Wizard: An Automated Multi-level Partitioning Tool on Analytical Workloads

  • Suh, Young-Kyoon;Crolotte, Alain;Kostamaa, Pekka
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.4
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    • pp.1693-1713
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    • 2018
  • An important technique used by database administrators (DBAs) is to improve performance in decision-support workloads associated with a Star schema is multi-level partitioning. Queries will then benefit from performance improvements via partition elimination, due to constraints on queries expressed on the dimension tables. As the task of multi-level partitioning can be overwhelming for a DBA we are proposing a wizard that facilitates the task by calculating a partitioning scheme for a particular workload. The system resides completely on a client and interacts with the costing estimation subsystem of the query optimizer via an API over the network, thereby eliminating any need to make changes to the optimizer. In addition, since only cost estimates are needed the wizard overhead is very low. By using a greedy algorithm for search space enumeration over the query predicates in the workload the wizard is efficient with worst-case polynomial complexity. The technology proposed can be applied to any clustering or partitioning scheme in any database management system that provides an interface to the query optimizer. Applied to the Teradata database the technology provides recommendations that outperform a human expert's solution as measured by the total execution time of the workload. We also demonstrate the scalability of our approach when the fact table (and workload) size increases.