Why functional dependencies guide schema design in DBMS Theory - Quick Recap

Recall & Review

beginner

What is a functional dependency in database design?

A functional dependency is a relationship where one set of attributes uniquely determines another attribute in a table. It helps ensure data consistency.

beginner

Why are functional dependencies important for schema design?

They help identify how data relates and guide organizing tables to reduce redundancy and avoid update problems.

intermediate

How do functional dependencies help prevent data anomalies?

By structuring tables based on dependencies, they avoid insertion, update, and deletion errors caused by redundant or inconsistent data.

intermediate

What role do functional dependencies play in normalization?

They define rules to split tables into smaller ones so each dependency is properly represented, improving data integrity.

beginner

Can ignoring functional dependencies cause problems in a database? Why?

Yes, ignoring them can cause duplicate data, inconsistent updates, and make the database harder to maintain.

What does a functional dependency indicate in a database?

A One attribute uniquely determines another

B Two tables are unrelated

C Data is stored in multiple places

D A table has no primary key

Functional dependency means one attribute or set of attributes uniquely determines another attribute.

Why do we use functional dependencies in schema design?

A To increase data duplication

B To reduce data redundancy and avoid anomalies

C To make queries slower

D To ignore relationships between data

Functional dependencies guide organizing data to reduce redundancy and prevent update problems.

Which problem can functional dependencies help prevent?

A Lack of data

B Faster data entry

C Data anomalies like inconsistent updates

D More storage space

They help avoid anomalies such as inconsistent or incorrect data updates.

In normalization, functional dependencies are used to:

A Split tables to represent dependencies properly

B Combine all data into one table

C Ignore attribute relationships

D Add redundant data

Normalization uses functional dependencies to organize tables for better data integrity.

What happens if functional dependencies are ignored?

A Tables become smaller

B Database runs faster

C Data becomes more secure

D Data redundancy and inconsistency increase

Ignoring dependencies leads to duplicate and inconsistent data, causing maintenance issues.

Explain how functional dependencies influence the design of a database schema.

Think about how one attribute determines another and why that matters for storing data.

Describe the connection between functional dependencies and normalization in databases.

Consider how dependencies guide breaking down tables into smaller parts.