Data Engineering Data Modeling and Schema Design

Question 1

Which schema design uses a central fact table surrounded by multiple dimension tables with no normalization of dimensions?

Accepted Answer

Star schema

Answer

Snowflake schema

Answer

Galaxy schema

Answer

Flat schema

Question 2

In a snowflake schema, dimension tables are normalized into multiple related tables primarily to:

Accepted Answer

Reduce storage redundancy

Answer

Improve query speed

Answer

Increase fact table rows

Answer

Simplify ETL processes

Question 3

What is a surrogate key in dimensional modeling?

Accepted Answer

A system-generated integer used as the primary key for a dimension

Answer

A natural business key from the source system

Answer

A composite key made of multiple columns

Answer

A foreign key referencing the fact table

Question 4

Which modeling approach is best suited for ad-hoc analytics and is optimized for read performance in data warehouses?

Accepted Answer

Dimensional modeling

Answer

Third Normal Form (3NF)

Answer

Entity-Relationship modeling

Answer

Graph modeling

Question 5

In data vault modeling, which component stores the unique business keys and acts as the hub of integration?

Accepted Answer

Hub

Answer

Link

Answer

Satellite

Answer

Bridge

Question 6

What does a 'degenerate dimension' refer to in dimensional modeling?

Accepted Answer

A dimension key stored in the fact table with no corresponding dimension table

Answer

A dimension with very low cardinality

Answer

A deprecated dimension no longer in use

Answer

A dimension derived from another dimension