The database designer creates a(n) _______ when no suitable single-column or composite primary key exists.

Question

BlackTom AI · Accepted Answer

The question asks about what a database designer creates when there is no suitable single-column or composite primary key.
First, consider the purpose of a primary key: to uniquely identify each row in a table. If no natural single column or combination of columns reliably guarantees uniqueness, a surrogate, non-business-related identifier is introduced solely to serve as a unique key.
Next, the term that describes this surrogate, artificially created identifier is an artificial key (also called a surrogate key). It has no intrinsic meaning to the data itself but provides a stable, unique reference for each record.
Why this is preferable in such cases: it avoids issues with composite keys becoming unwieldy, ensures performance for joins, and remains stable even if other data attributes change, since the artificial key does not carry business meaning.
Regarding potential misconceptions: some might think a natural key must always exist, but when it doesn’t, introducing an artificial key is a standard and sound database design practice. Other options like trying to force a single column to be a primary key despite not guaranteeing uniqueness would violate core database principles. Similarly, using multiple natural attributes as a primary key can complicate foreign-key relationships and indexing, especially if those attributes can change or are not consistently present.
In short, when a proper natural or composite key isn’t available, an artificial (surrogate) key is created to serve as the primary key, supporting reliable uniqueness and referential integrity without tying the key to real-world data values.

The database designer creates a(n) _______ when no suitable single-column or composite primary key exists.单项选择题

类似问题

People are not born with 'Numbers,' but many systems assign student numbers, customer IDs, etc., to individuals. These are known as a/an ___________________ key.

以下哪张图属于私密照片？

What is difference between ‘disclosures’ and ‘complaints’ at the University of Sydney?

Which of the following best describes intersectionality in the context of understanding relationship dynamics?

28岁的杰米患有精神分裂症，经常出现妄想和思维混乱。一天晚上，他和伴侣泰勒在沙发上讨论性行为。杰米似乎心不在焉，难以清晰地表达自己的想法。哪些因素可能会影响杰米做出知情同意的能力？

What are some barriers international students might face when reporting sexual harm or gender-based violence?

Which scenario best demonstrates an unhealthy power imbalance in a relationship?

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单