This paper deals with the semantics of null values in functional dependencies in database theory, and presents three different definitions of FDs in a single relation with marked nulls.
本文研究关系数据库理论中空值在函数依赖中的语义问题，提出了带标志空值的关系中函数依赖的三种定义。
The theory behind atomic transactions, rollbacks, and other critical database topics are very similar to the issues students study in operating systems.
原子事务、回滚和其它关键的数据库主题背后的理论非常类似于学生在操作系统中学习的问题。
That approach may sound straightforward in theory, but in practice the vast variety of database structures and possible search terms poses a thorny computational challenge.
这种做法可能在理论上听起来很简捷，但在实践中大量各种不同的数据库结构和可能的搜索词构成了一个棘手的计算挑战。
Manipulations like this (backed by the proper relational theory) are at the heart of database query optimizers. The resulting tree is shown in Figure 2.
此类操作(由恰当的关系理论作为支持)是数据库查询优化器的核心所在。
It begins with the theory of intrusion tolerant, discusses a design of the database using the theory and the realizing of ballot in such a system.
从入侵容忍的理论入手，论述了一种入侵容忍的数据库系统的设计方案和在该系统中进行选举的实现过程。
Seeking for candidate key of relation scheme is an important question in designing database theory.
寻找关系模式的候选码是数据库设计理论中的重要问题。
Rough Sets theory has great superiority in Data Preprocessing because of its particular expression of knowledge, as well as it makes an effective means of knowledge Discovery in Database.
粗糙集理论由于其独特的知识表示方法在数据预处理方面有着得天独厚的优势，同时也成为数据库中知识发现的有效手段。
In theory, you can perform select, insert, update, or delete statements against a table that is not yet redistributed in the database partition group.
理论上讲，可以在数据库分区组中尚未重分发的表上执行select、insert、update或delete语句。
In this paper, it researches and realizes the mapping theory between the object and relational database, and manages the persistent objects.
论文对数据对象与关系数据库之间映射理论和持久化对象管理技术进行了研究和实现。
In research of active database's theory and application, the application of update propagation maintains the consistency of database system in attribute dependency.
在主动数据库的理论与应用研究中，更新传播算法的应用，保证了系统在属性依赖方面的相容性。
In normalization theory of relation database, finding candidate key and primary attribute is always a difficult problem.
在关系数据库规范化理论中，求解后选关键字和主属性一直是一个棘手的问题。
The third section introduces how the RS theory is applied in the decision making with an enterprise database.
第三部分通过具体的企业销售数据库实例，介绍粗糙集方法在管理决策中的应用过程。
Second, it introduces the related theory of the distributed database system and software engineering used in the project.
接着介绍了在系统开发中用到的分布式数据库技术的理论和软件工程理论；
In these foundations, the recursion theory of depth first traversal, database technology and visual programming technology are employed to computer memory, which is expressed to node relations.
在此基础上，采用深度优先遍历的递归理论和数据库技术，实现了流域节点间关系的计算机存储。
Join dependency in relational data theory is not seldom seen during database systems designing.
本文阐明关系数据规范理论中的连接依赖在设计数据库系统时并不少见。
Data mining is a theory forward in the field of database and decision-making information, It is core of the knowledge discovery.
数据挖掘是数据库和信息决策领域的一个理论前沿，是知识发现的核心部分。
The database of the agricultural information service system is designed in use of database design theory, method and process.
利用数据库设计理论、方法与步骤对农业信息服务系统数据库进行了设计。
Secondly, the basic theory and realization methods of the real-time embedded database 's fundamental functions are discussed in the paper.
其次，本文讨论了实时嵌入式数据库基本功能实现的理论基础和实现方法。
As the application of information technology enlarges its scope in the fields of land and mineral resources, the theory, technology and practice of spatial database concept become very complete.
随着信息技术在国土资源部门的广泛应用，空间数据库理论、技术和实践日臻成熟。
Transaction is one of the core concepts in modern database theory, and concurrency control technology is the major component of transaction management.
事务是现代数据库理论中的核心概念之一，并发控制是事务管理的主要组成部分。
The thesis combines database theory with practical business analysis, developing theoretical and practical work in software structure of business system, its chief work is as followings.
本文把数据仓库理论和实际的业务分析相结合，在数据仓库的建设、业务分析系统的软件架构方面开展了理论和实践工作，主要的工作表现在。
In addition, the realizing parts of the MMDB system include database file format and the theory of database process schedule.
主存数据库系统设计与实现的其它部分还包括数据库文件格式和数据库进程调度的原理。
In the relation of the database theory of the computer, we encounter some problems which can be translated into the problem for parameter and Hamilton cycle of double graphs or complement graphs.
计算机科学数据库的关系中遇到了可归为倍图或补倍图的参数和哈密顿圈的问题。
Based on theory researches and practical development conditions of fuzzy database, some problems about knowledge discovery are explored in the crime fuzzy database.
根据模糊数据库的理论研究及实际开发状况，对犯罪模糊数据库中知识发现的几个问题进行了探讨。
In theory, database doesn't even require a computer, but it certainly makes its use a lot more scalable and efficient.
理论上讲，数据库甚至可以不需要计算机，但它一定会使其用途有大得多的可扩展性和效率。
The problem of normalization for object is the kernel problem in normalization theory for object-oriented database.
对象规范化问题是面向对象规范化理论中的核心问题。
The traditional rough set theory can only deal with the discrete attribute in a database, so it is necessary to deal with the consistent attribute when the consistent attributes exist in a database.
传统的粗糙集理论只能对数据库中的离散属性进行处理，所以对存在连续属性的数据库必须进行离散化处理。
We passed on the database management system, language theory and application design a more in-depth study and application, combined with hotel rooms management requirements.
我们通过对数据库管理系统、语言原理及应用程序设计等进行了较深入的学习和应用，并结合酒店客房管理的要求。
We passed on the database management system, language theory and application design a more in-depth study and application, combined with hotel rooms management requirements.
我们通过对数据库管理系统、语言原理及应用程序设计等进行了较深入的学习和应用，并结合酒店客房管理的要求。
应用推荐