functional dependency

简明释义

函数相关性

英英释义

例句

1.Understanding functional dependency 函数依赖 is crucial for creating efficient database schemas.

理解函数依赖对创建高效的数据库模式至关重要。

2.A primary key must uniquely identify a record, which implies that there cannot be any functional dependency 函数依赖 violations.

主键必须唯一标识一条记录，这意味着不能有任何函数依赖违规。

3.In relational databases, the concept of functional dependency 函数依赖 helps in understanding how data is related.

在关系数据库中，函数依赖的概念有助于理解数据是如何相关的。

4.In database design, a table should be normalized to eliminate any functional dependency 函数依赖 that could lead to data redundancy.

在数据库设计中，应该对表进行规范化，以消除任何可能导致数据冗余的函数依赖。

5.When two attributes are related, one may exhibit a functional dependency 函数依赖 on the other.

当两个属性相关时，一个可能会对另一个表现出函数依赖。

作文

In the realm of database management systems, the concept of functional dependency plays a crucial role in ensuring data integrity and optimizing database design. A functional dependency occurs when one attribute uniquely determines another attribute within a relation. This relationship is fundamental to understanding how data is organized and accessed in relational databases. For instance, consider a simple database for a library system where each book is identified by a unique ISBN number. If we say that the ISBN number functionally determines the book title, we can express this as ISBN → Title. This means that for every unique ISBN, there is exactly one corresponding book title. Understanding functional dependency is essential for database normalization, which aims to reduce data redundancy and improve data integrity. Normalization involves organizing the fields and tables of a database to minimize duplication of information. By identifying functional dependencies, database designers can create tables that are structured in such a way that they eliminate unnecessary data repetition. For example, if we have a table that contains information about authors and their books, we might find that an author’s name is dependent on their unique author ID. In this case, we can say AuthorID → AuthorName. This indicates that each author ID corresponds to one specific author name, reinforcing the importance of functional dependency in establishing clear relationships between different pieces of data.Moreover, functional dependency also assists in enforcing constraints within the database. Constraints are rules that ensure the accuracy and reliability of the data stored. By defining functional dependencies, we can set up rules that prevent anomalies during data operations like insertion, deletion, or updating records. For instance, if we were to delete a record of a book based on its ISBN, the database must ensure that the associated title is also removed to maintain consistency. This demonstrates how functional dependency not only aids in structuring the database but also in maintaining its integrity over time.In conclusion, the concept of functional dependency is integral to the field of database management. It helps in organizing data efficiently, reduces redundancy, and enforces data integrity through established relationships. As we continue to rely more heavily on data-driven decision-making, understanding functional dependency will become increasingly important for database administrators and developers alike. Mastering this concept is essential for anyone looking to excel in the field of data management and analytics, as it lays the groundwork for effective database design and maintenance.

在数据库管理系统领域，函数依赖的概念在确保数据完整性和优化数据库设计方面发挥着至关重要的作用。函数依赖发生在一个属性唯一确定关系中的另一个属性时。理解这一关系对于理解数据在关系数据库中如何组织和访问至关重要。例如，考虑一个简单的图书馆系统数据库，其中每本书都由唯一的ISBN编号标识。如果我们说ISBN编号函数上决定书名，我们可以将其表示为ISBN → Title。这意味着对于每个唯一的ISBN，恰好有一个对应的书名。理解函数依赖对于数据库规范化至关重要，规范化旨在减少数据冗余并提高数据完整性。规范化涉及组织数据库的字段和表，以最小化信息的重复。通过识别函数依赖，数据库设计师可以创建结构合理的表，从而消除不必要的数据重复。例如，如果我们有一个包含作者及其书籍信息的表，我们可能会发现作者的姓名依赖于其唯一的作者ID。在这种情况下，我们可以说AuthorID → AuthorName。这表明每个作者ID对应于一个特定的作者姓名，进一步强调了函数依赖在建立不同数据片段之间清晰关系中的重要性。此外，函数依赖还有助于在数据库中强制执行约束。约束是确保存储的数据准确性和可靠性的规则。通过定义函数依赖，我们可以设置规则，防止在插入、删除或更新记录等数据操作过程中出现异常。例如，如果我们根据ISBN删除一本书的记录，数据库必须确保关联的书名也被删除，以保持一致性。这展示了函数依赖不仅有助于构建数据库，而且在维护其长期完整性方面也发挥了作用。总之，函数依赖的概念在数据库管理领域至关重要。它有助于有效地组织数据，减少冗余，并通过建立关系来强制执行数据完整性。随着我们越来越依赖数据驱动的决策，理解函数依赖将变得愈发重要，特别是对于数据库管理员和开发人员而言。掌握这一概念是任何希望在数据管理和分析领域取得成功的人的基本功，因为它为有效的数据库设计和维护奠定了基础。