DBMS Group 8 Review Quiz

Why are conformed dimensions important in a data warehouse?

• They allow different fact tables to share the same business meaning

• They increase data redundancy for better storage optimization

• They separate unrelated business processes in different data marts

• They are used only in OLTP databases

Which of the following is NOT a valid reason for using multiple fact tables in a star schema?

• Different levels of data aggregation

• Storing different business processes

• Improving query performance

• Reducing data redundancy by eliminating dimension tables 

What is the primary difference between a fact table and a dimension table?

• Fact tables store descriptive data, while dimension tables store numerical data

• Fact tables store business events, while dimension tables provide context

• Fact tables always contain text-based information

• Dimension tables store aggregated data

Why is a helper table more scalable than a denormalized table?

• It stores multiple values in a single column

• It eliminates data redundancy and allows unlimited relationships

• It increases the size of the database significantly

• It requires modifying the entire row for every update

What is the primary advantage of using a helper table for many-to-many relationships?

• It reduces the number of queries needed

• It stores all possible values in one row

• It makes data retrieval faster and updates more efficient

• It removes the need for indexing

In a student-course database, how would you efficiently store a many-to-many relationship?

• By adding multiple course columns in the student table

• By storing all courses in a single text column separated by commas

• By using a helper table to track student-course relationships

• By creating a separate table for each student

What is a factless fact table?

• A table that stores numerical measures like sales amounts.

• A table that tracks events or coverage using foreign keys but no measures

• A table that only stores descriptive data about dimensions.

• A table that stores aggregated data for reporting.

Which of the following is a common use case for a factless fact table?

• Tracking student attendance in classes

• Storing sales revenue and quantitiesCalculating profit margins

• Calculating profit margins

• Storing customer addresses

What is the primary purpose of foreign keys in a factless fact table?

• To store numerical data like sales amounts

• To store descriptive data about business processes

• To perform calculations like sums and averages

• To link to dimension tables and provide context for the data

What is the primary purpose of a hierarchy in data warehousing?

• To store all data in a single table

• To increase redundancy in data storage

• To allow users to drill down or roll up data for analysis at different levels of granularity

• To replace fact tables in a database