Version control in data modeling helps to ensure _______ of data models.

  • Collaboration
  • Consistency
  • Flexibility
  • Security
Version control ensures consistency of data models by tracking changes and allowing users to revert to previous states if needed. It prevents conflicts and discrepancies, providing a stable and reliable model over time.

What are the advantages of using a Star Schema over a Snowflake Schema in data warehousing?

  • Better suited for normalized data
  • Easier to understand and navigate
  • More suitable for complex analytical queries
  • Reduced query complexity
One advantage of using a Star Schema over a Snowflake Schema is reduced query complexity. In a Star Schema, all dimensional data is stored in a single table, making it simpler and faster for querying compared to the normalized structure of a Snowflake Schema, which involves multiple tables and joins.

Which type of relationship in an ERD allows an entity to be related to itself?

  • Many-to-Many
  • One-to-One
  • Recursive
  • Weak
A recursive relationship in an ERD allows an entity to be related to itself. This scenario often occurs when an entity has a relationship with instances of the same entity type. It is useful in modeling hierarchical structures and network relationships.

What is a Data Mart?

  • A storage device for temporary data
  • A subset of a data warehouse that focuses on a specific business area
  • A tool for data encryption
  • A type of database management system
A Data Mart is a subset of a data warehouse that is focused on a specific business area or topic. It contains a tailored set of data that is designed to meet the needs of a particular group of users, providing a more specialized and targeted view of the data.

In SQL, a _______ statement is used to define the structure of a database.

  • CREATE
  • INSERT
  • SELECT
  • UPDATE
In SQL, the CREATE statement is used to define the structure of a database. It allows you to create tables, define relationships, and set constraints, shaping the overall architecture of the database.

What are some best practices for managing conflicts in version control for data modeling?

  • Ignoring conflicts to maintain stability
  • Regularly merging changes from different branches
  • Restricting access to version control
  • Utilizing a centralized version control system
Best practices for managing conflicts include regularly merging changes from different branches. This ensures that updates from various contributors are incorporated, reducing conflicts and maintaining a consistent data model across the team.

Scenario: A company wants to ensure that every order placed in their system has a corresponding customer. Which type of constraint would you apply to the order table to enforce this rule?

  • Check Constraint
  • Foreign Key Constraint
  • Primary Key Constraint
  • Unique Constraint
To ensure that every order has a corresponding customer, you would apply a Foreign Key Constraint to the order table. This constraint establishes a link between the order table and the customer table, preventing orders without a matching customer.

In a relational database, what does a one-to-many relationship imply?

  • Each record in the "many" table can be related to multiple records in the "one" table
  • Each record in the "many" table can be related to only one record in the "one" table
  • Each record in the "one" table can be related to multiple records in the "many" table
  • Each record in the "one" table can be related to only one record in the "many" table
A one-to-many relationship in a relational database implies that each record in the "one" table can be related to multiple records in the "many" table. This type of relationship is fundamental in database design and is often represented using foreign keys.

_______ is the process of reorganizing data into separate sections to improve manageability and performance.

  • Denormalization
  • Normalization
  • Partitioning
  • Sharding
Partitioning is the process of reorganizing data into separate sections or partitions. This technique helps in managing large datasets more efficiently, improving query performance, and optimizing data storage and retrieval processes.

What are the key differences between a fact table and a transactional table in a relational database?

  • Fact tables are used for online transaction processing (OLTP), while transactional tables are used for online analytical processing (OLAP)
  • Fact tables contain aggregated data, while transactional tables store detailed, raw data
  • Fact tables have a primary key, while transactional tables have foreign keys
  • Fact tables store current data, while transactional tables store historical data
Fact tables in a relational database store aggregated data, often derived from transactional tables. Transactional tables, on the other hand, store detailed, raw data. Recognizing these differences is essential for efficient database design and querying in both OLAP and OLTP environments.