全序时态初等关键字范式研究
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摘要
时态信息存在于生活中的每一角落,计算机技术总是科技发展的前沿,因此时态信息与数据库技术结合的应用需求越来越广泛,时态数据库也就应运而生。关系数据库理论中,关系模式的分解是消除数据冗余及存储异常的有效途径。在时态数据库设计中,时态模块模式分解问题同样值得深入研究。实际上在应用中遇到的大部分时间粒度之间都具有全序关系,这种全序关系使得全序时态类型集具有重要特性,所以本文针对全序时态数据库的模式分解问题进行分析研究。
为了更有效的研究时态数据库模式分解问题,以便进一步规范化,本文首先对全序时态候选关键字的求解进行研究,概括了全序时态左、右部和双部属性。结合关系型数据库理论给出替换算法和时态属性相关表法求全部全序候选关键字,并对相关定理推论进行证明。
当把一个全序时态模块模式分解成全序时态三范式时并不能消除某些时态数据的冗余,对于分解成全序时态BC范式的情况则只能保证全序无损连接性,对于保持依赖则很难做到。这样我们就有必要定义一种新的范式来解决以上两种范式出现的问题,因此本文提出了全序初等函数依赖、全序初等候选关键字、全序时态初等关键字范式等概念来达到这一目的,利用全序时态最小覆盖集的特性给出属于全序时态初等关键字范式的模式分解算法,并对相关定理推论进行分析讨论。
以上理论和算法的研究,很好的解决了全序时态模块模式向全序时态初等关键字范式的规范,为时态数据库逻辑设计发展铺路。
Temporal information exists in every corner of our life. Computer technology is always leading the development of science and technology, therefore the applications on the combination of temporal information with database technology are needed more and more widely. Just at this moment arises temporal database. In the relational database theory, relational scheme decomposition is an effective way to eliminate redundant data and storage anomaly. In designing temporal database, decomposition of temporal module scheme is also worth our researching in depth. Actually the totally-ordered relation exists among the most of time granularities encountered in application. It is also this totally-ordered relation that makes the totally-ordered temporal type take on some important characteristics, therefore this paper mainly studies the problems of scheme decomposition of totally-ordered temporal database.
In order to more effectively research the problem of scheme decomposition of temporal database for further standardization, this paper firstly investigates totally-ordered temporal candidate keywords and summarizes the attributes of the totally-ordered temporal left, right department and double department. All the totally-ordered candidate keywords can be obtained through the combination with the relational database theory and the introduction of replacement algorithm and temporal attributes related table method. And the relevant theorems and deductions will be demonstrated.
It cannot eliminate some temporal data redundancy just by decomposing a totally-ordered temporal scheme into totally-ordered temporal third normal form. Only the totally-ordered and lossless connectivity can be maintained when a totally-ordered temporal scheme is decomposed into totally-ordered temporal BC normal form. It is difficult to accomplish the preservation of functional dependencies in this condition. So it is necessary for us to find a new normal form to alleviate these problems. To achieve this goal, this paper puts forward such concepts as totally-ordered elementary functional dependent, totally-ordered elementary candidate keys, totally-ordered temporal elementary key normal form concepts, using the characteristics of totally-ordered minimal cover sets present the decomposition algorithm of totally-ordered temporal elementary key normal form scheme, and discusses and analyzes the related theorem and deductions.
The study of the theories and algorithms as above will effectively solve the problem of normalizing totally-ordered temporal scheme to totally-ordered temporal elementary key normal form, and pave the way for temporal database logical design.
为了更有效的研究时态数据库模式分解问题,以便进一步规范化,本文首先对全序时态候选关键字的求解进行研究,概括了全序时态左、右部和双部属性。结合关系型数据库理论给出替换算法和时态属性相关表法求全部全序候选关键字,并对相关定理推论进行证明。
当把一个全序时态模块模式分解成全序时态三范式时并不能消除某些时态数据的冗余,对于分解成全序时态BC范式的情况则只能保证全序无损连接性,对于保持依赖则很难做到。这样我们就有必要定义一种新的范式来解决以上两种范式出现的问题,因此本文提出了全序初等函数依赖、全序初等候选关键字、全序时态初等关键字范式等概念来达到这一目的,利用全序时态最小覆盖集的特性给出属于全序时态初等关键字范式的模式分解算法,并对相关定理推论进行分析讨论。
以上理论和算法的研究,很好的解决了全序时态模块模式向全序时态初等关键字范式的规范,为时态数据库逻辑设计发展铺路。
Temporal information exists in every corner of our life. Computer technology is always leading the development of science and technology, therefore the applications on the combination of temporal information with database technology are needed more and more widely. Just at this moment arises temporal database. In the relational database theory, relational scheme decomposition is an effective way to eliminate redundant data and storage anomaly. In designing temporal database, decomposition of temporal module scheme is also worth our researching in depth. Actually the totally-ordered relation exists among the most of time granularities encountered in application. It is also this totally-ordered relation that makes the totally-ordered temporal type take on some important characteristics, therefore this paper mainly studies the problems of scheme decomposition of totally-ordered temporal database.
In order to more effectively research the problem of scheme decomposition of temporal database for further standardization, this paper firstly investigates totally-ordered temporal candidate keywords and summarizes the attributes of the totally-ordered temporal left, right department and double department. All the totally-ordered candidate keywords can be obtained through the combination with the relational database theory and the introduction of replacement algorithm and temporal attributes related table method. And the relevant theorems and deductions will be demonstrated.
It cannot eliminate some temporal data redundancy just by decomposing a totally-ordered temporal scheme into totally-ordered temporal third normal form. Only the totally-ordered and lossless connectivity can be maintained when a totally-ordered temporal scheme is decomposed into totally-ordered temporal BC normal form. It is difficult to accomplish the preservation of functional dependencies in this condition. So it is necessary for us to find a new normal form to alleviate these problems. To achieve this goal, this paper puts forward such concepts as totally-ordered elementary functional dependent, totally-ordered elementary candidate keys, totally-ordered temporal elementary key normal form concepts, using the characteristics of totally-ordered minimal cover sets present the decomposition algorithm of totally-ordered temporal elementary key normal form scheme, and discusses and analyzes the related theorem and deductions.
The study of the theories and algorithms as above will effectively solve the problem of normalizing totally-ordered temporal scheme to totally-ordered temporal elementary key normal form, and pave the way for temporal database logical design.
引文
[1]辜炜东,汤庸,王路帮等.事务数据库中的时态信息挖掘[J].计算机工程与应用,2004,40(18):174-177.
[2]师胜利,董瑞卿,杨彦锡.时态数据库在电子商务中的应用[J].计算机与信息技术,2008,(3):73-74.
[3]刘云生.现代数据库技术[M].北京:国防工业出版社,2001:21-53.
[4] JENSEN C S, CLIFFORD J. A Glossary of Temporal Database Concepts[J]. ACM SIGMOD Record, 1994, 23(1): 52-64.
[5] TANSEL A, CLIFFORD J, GADIA J S. Temporal Databases: Theory, Design and Implementation[J]. Database Systems and Applications Series, 1993, (5): 35-40.
[6]汤庸.时态知识和时态数据库的统一模型研究[J].软件学报,2003,(12):74-78.
[7] SHASHI K G, SEO Y N. Benchmarking Temporal Database Models withInterval-based and Temporal Element-based Timestamping[J]. Journal of Systems and Software, 2008, 81(11): 1931-1943.
[8]郝忠孝.关系数据库数据理论新进展[M].北京:机械工业出版社,1998:31-47.
[9] EDELWEISS N, HUBLER P N, DEMARTINI G. A Temporal Database Management System Implemented on Top of a Conventional Database[J].IEEE Computer Society, 2000, (11): 551-631.
[10] BETTINI G, WANG X S, JAJODIA S. A Generak Framework and Reasoning Models for Time Granularity[J]. Workshop on Temporal Representation and Reasoning, 1996, (5): 256-304.
[11] WANG X S, BETTINI C, JAJODIA S. Logical Design for Temporal Databases with Multiple Granularities[J]. ACM Transactions on Database System: 1997, 22(2): 115-170.
[12] ABRAHAM S, HENRY F K, S.SUDARSHAN. Database System Concepts[M].杨冬青,马秀莉,唐世渭等,译.北京:机械工业出版社,2008:167-198.
[13]龚冰.多粒度双时态数据模型的研究与应用[D].河北:燕山大学,2005:8-9.
[14]汤庸.时态知识和时态数据库的统一模型研究[J].软件学报,2003,(12):74-78.
[15] DYRESON C E, EVANS W S. Efficiently Supporting Temporal Granularities[J]. IEEE Transactions on Knowledge and Data Engineering, 2000, 12(4): 568-586.
[16]安蓓,赵政.面向对象的时态数据库技术研究[D].天津:天津大学,2006:1-32.
[17] SLIVINSKAS G, JENSEN C S, SNODGRASS R T. Adaptable Query Optimization and Evaluation in Temporal Middleware[C]. Association for Computing Machinery. 2001 ACM SIGMOD International Conference on Management of Data, Santa Barbara CA United States, 2001:127-138.
[18] JENSEN C S, SNNODGRASS R T. Temporal Data Management[J]. IEEETransactions on Knowledge and Data Engieering, 1999, 1(11):36-44.
[19]唐常杰.时态数据库的沿革、特色与代表人物—时态数据库二十年回顾之一[J].计算机科学,1999,26(2):27-29.
[20] JENSEN C S, SNODGRASS R T. Temporally Enhanced Database Design[M]. In: Advances in Object-Oriented Data Modeling. Cambridge, USA: MIT Press, 2000, 163-193.
[21] JENSEN C S, SNODGRASS R T, SOO M D. Extending Existing Dependency Theory to Temporal Databases[J]. IEEE Transactions on Knowledge and Data Engineering, 1996, 8(4): 563-582.
[22] WIJSEN J. Trends in Databases: Reasoning and Mining[J]. IEEE Transactions on Knowledge and Data Engineering, 2001, (5): 78-93.
[23] WIJSEN J, VANDENBULCKE J, OLIVE H. Functional Dependencies Generalized for Temporal Databases that Include object-identity[C]. Springer-Verlag GmbH & Company KG. Proceedings of the 12th International Conference on the Entity-Relationship Approach, Arlington, 1994: 99.
[24] WIJSEN J. Temporal FDs on complex objects[J]. ACM Transactions on Database System, 1999, 24(1): 127-176.
[25] WIJSEN J. Design of Temporal Relational Databases Based on Dynamic and Temporal Functional Dependencies[J]. In: Proc of the International Workshop on Recent Advances in Temporal Databases, 1995: 61-76.
[26] LIU WEI YI. SONG NING. A Logical Design Method for Temporal Databases Based on the Stability Constraint and the Generatlization Semantics[J]. Information Sciences, 2000, 124(1-4): 153-171.
[27]赵磊,徐士华.具有多时间粒度的时态数据库规范化问题研究[J].自然科学学报,2006,22(3):55-58.
[28]唐常杰.时态数据库的成果、缺陷与未来—时态数据库二十年回顾之二[J].计算机科学,1999,26(3):63-65.
[29]汤庸.时态数据库导论[M].北京:北京大学出版社,2004:7-32.
[30]姚春龙,郝忠孝.时态类型集的封闭集[J].计算机工程,2003,2:35-37.
[31]姚春龙,多时间性粒度下时态数据库设计理论研究[D].哈尔滨:哈尔滨工业大学,2004,(4):34.
[32]刘宁.时态数据库多时间粒度问题的研究[D].哈尔滨:哈尔滨理工大学,2005:10-16.
[33]姚春龙,郝忠孝.具有全序时态类型集时态函数依赖集的研究[J].软件学报,2003,14(2):247-252
[34]姚春龙,郝忠孝.一个多时间粒度下时态函数依赖集的有限属性闭包算法[J].计算机研究与发展,2005,42(3):443-454.
[35]郝忠孝,刘宁.多时间粒度约束的时态简单范式的分解[J].计算机工程,2006,32(4):73-78.
[36]李艳娟,郝忠孝.属性集的有限闭包与有限依赖基算法[J].哈尔滨理工大学学报,2005,2(10):19-22.
[37]郝忠孝,李艳娟.时态函数依赖多值依赖混合集的成员籍问题研究[J].计算机研究与发展,2006,43(7):1267-1272.
[38]郝忠孝,李艳娟.具有多时间粒度的时态多值依赖及时态模式分解方法研究[J].计算机研究与发展,2007,44(5):853-859.
[39]万静,杨洪玉,郝忠孝.全序时态模式中时态函数依赖的覆盖问题研究[J].计算机应用研究,2009,26(12):4517-4517.
[40]万静,郝忠孝.全序时态模块模式的TO_TSNF分解问题研究[J].计算机科学,2007,34(3):35-39.
[2]师胜利,董瑞卿,杨彦锡.时态数据库在电子商务中的应用[J].计算机与信息技术,2008,(3):73-74.
[3]刘云生.现代数据库技术[M].北京:国防工业出版社,2001:21-53.
[4] JENSEN C S, CLIFFORD J. A Glossary of Temporal Database Concepts[J]. ACM SIGMOD Record, 1994, 23(1): 52-64.
[5] TANSEL A, CLIFFORD J, GADIA J S. Temporal Databases: Theory, Design and Implementation[J]. Database Systems and Applications Series, 1993, (5): 35-40.
[6]汤庸.时态知识和时态数据库的统一模型研究[J].软件学报,2003,(12):74-78.
[7] SHASHI K G, SEO Y N. Benchmarking Temporal Database Models withInterval-based and Temporal Element-based Timestamping[J]. Journal of Systems and Software, 2008, 81(11): 1931-1943.
[8]郝忠孝.关系数据库数据理论新进展[M].北京:机械工业出版社,1998:31-47.
[9] EDELWEISS N, HUBLER P N, DEMARTINI G. A Temporal Database Management System Implemented on Top of a Conventional Database[J].IEEE Computer Society, 2000, (11): 551-631.
[10] BETTINI G, WANG X S, JAJODIA S. A Generak Framework and Reasoning Models for Time Granularity[J]. Workshop on Temporal Representation and Reasoning, 1996, (5): 256-304.
[11] WANG X S, BETTINI C, JAJODIA S. Logical Design for Temporal Databases with Multiple Granularities[J]. ACM Transactions on Database System: 1997, 22(2): 115-170.
[12] ABRAHAM S, HENRY F K, S.SUDARSHAN. Database System Concepts[M].杨冬青,马秀莉,唐世渭等,译.北京:机械工业出版社,2008:167-198.
[13]龚冰.多粒度双时态数据模型的研究与应用[D].河北:燕山大学,2005:8-9.
[14]汤庸.时态知识和时态数据库的统一模型研究[J].软件学报,2003,(12):74-78.
[15] DYRESON C E, EVANS W S. Efficiently Supporting Temporal Granularities[J]. IEEE Transactions on Knowledge and Data Engineering, 2000, 12(4): 568-586.
[16]安蓓,赵政.面向对象的时态数据库技术研究[D].天津:天津大学,2006:1-32.
[17] SLIVINSKAS G, JENSEN C S, SNODGRASS R T. Adaptable Query Optimization and Evaluation in Temporal Middleware[C]. Association for Computing Machinery. 2001 ACM SIGMOD International Conference on Management of Data, Santa Barbara CA United States, 2001:127-138.
[18] JENSEN C S, SNNODGRASS R T. Temporal Data Management[J]. IEEETransactions on Knowledge and Data Engieering, 1999, 1(11):36-44.
[19]唐常杰.时态数据库的沿革、特色与代表人物—时态数据库二十年回顾之一[J].计算机科学,1999,26(2):27-29.
[20] JENSEN C S, SNODGRASS R T. Temporally Enhanced Database Design[M]. In: Advances in Object-Oriented Data Modeling. Cambridge, USA: MIT Press, 2000, 163-193.
[21] JENSEN C S, SNODGRASS R T, SOO M D. Extending Existing Dependency Theory to Temporal Databases[J]. IEEE Transactions on Knowledge and Data Engineering, 1996, 8(4): 563-582.
[22] WIJSEN J. Trends in Databases: Reasoning and Mining[J]. IEEE Transactions on Knowledge and Data Engineering, 2001, (5): 78-93.
[23] WIJSEN J, VANDENBULCKE J, OLIVE H. Functional Dependencies Generalized for Temporal Databases that Include object-identity[C]. Springer-Verlag GmbH & Company KG. Proceedings of the 12th International Conference on the Entity-Relationship Approach, Arlington, 1994: 99.
[24] WIJSEN J. Temporal FDs on complex objects[J]. ACM Transactions on Database System, 1999, 24(1): 127-176.
[25] WIJSEN J. Design of Temporal Relational Databases Based on Dynamic and Temporal Functional Dependencies[J]. In: Proc of the International Workshop on Recent Advances in Temporal Databases, 1995: 61-76.
[26] LIU WEI YI. SONG NING. A Logical Design Method for Temporal Databases Based on the Stability Constraint and the Generatlization Semantics[J]. Information Sciences, 2000, 124(1-4): 153-171.
[27]赵磊,徐士华.具有多时间粒度的时态数据库规范化问题研究[J].自然科学学报,2006,22(3):55-58.
[28]唐常杰.时态数据库的成果、缺陷与未来—时态数据库二十年回顾之二[J].计算机科学,1999,26(3):63-65.
[29]汤庸.时态数据库导论[M].北京:北京大学出版社,2004:7-32.
[30]姚春龙,郝忠孝.时态类型集的封闭集[J].计算机工程,2003,2:35-37.
[31]姚春龙,多时间性粒度下时态数据库设计理论研究[D].哈尔滨:哈尔滨工业大学,2004,(4):34.
[32]刘宁.时态数据库多时间粒度问题的研究[D].哈尔滨:哈尔滨理工大学,2005:10-16.
[33]姚春龙,郝忠孝.具有全序时态类型集时态函数依赖集的研究[J].软件学报,2003,14(2):247-252
[34]姚春龙,郝忠孝.一个多时间粒度下时态函数依赖集的有限属性闭包算法[J].计算机研究与发展,2005,42(3):443-454.
[35]郝忠孝,刘宁.多时间粒度约束的时态简单范式的分解[J].计算机工程,2006,32(4):73-78.
[36]李艳娟,郝忠孝.属性集的有限闭包与有限依赖基算法[J].哈尔滨理工大学学报,2005,2(10):19-22.
[37]郝忠孝,李艳娟.时态函数依赖多值依赖混合集的成员籍问题研究[J].计算机研究与发展,2006,43(7):1267-1272.
[38]郝忠孝,李艳娟.具有多时间粒度的时态多值依赖及时态模式分解方法研究[J].计算机研究与发展,2007,44(5):853-859.
[39]万静,杨洪玉,郝忠孝.全序时态模式中时态函数依赖的覆盖问题研究[J].计算机应用研究,2009,26(12):4517-4517.
[40]万静,郝忠孝.全序时态模块模式的TO_TSNF分解问题研究[J].计算机科学,2007,34(3):35-39.
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