Which of the following is NOT a common criterion for data partitioning?
- Alphabetical order
- Data type
- Date range
- Geography
Alphabetical order is NOT a common criterion for data partitioning. Data partitioning strategies typically focus on criteria such as data type, geography, and date range to organize and manage data effectively.
In Dimensional Modeling, a _______ key is a surrogate key generated to uniquely identify each record in a dimension table.
- Composite
- Foreign
- Primary
- Surrogate
In Dimensional Modeling, a surrogate key is a unique identifier generated for a dimension table. It replaces the natural key to provide a stable and efficient way to uniquely identify records, especially when dealing with slowly changing dimensions. This enhances data warehouse performance and simplifies data management.
Implementing data partitioning often requires careful consideration of _______ to ensure optimal performance.
- Data consistency
- Indexing strategies
- Network bandwidth
- Query complexity
Implementing data partitioning often requires careful consideration of network bandwidth to ensure optimal performance. Efficient data movement between partitions relies on a robust network infrastructure to prevent bottlenecks and maintain the overall effectiveness of the partitioning strategy.
In relational database terminology, what does referential integrity mean?
- Allows NULL values in a foreign key column
- Enforces unique constraints on multiple columns
- Ensures that foreign key values match the primary key values in another table
- Ensures that primary key values are unique
Referential integrity in a relational database means ensuring that foreign key values match the primary key values in another table. This prevents orphaned rows and maintains consistency in relationships between tables.
A _______ key is a combination of two or more columns that uniquely identifies a record in a table.
- Alternate
- Composite
- Foreign
- Super
A Composite Key is a combination of two or more columns that uniquely identifies a record in a table. Unlike a single-column key, a composite key provides a more granular level of uniqueness in data.
Scenario: An online store has various types of products, including electronics and clothing. Each product has common attributes like name and price, but they also have specific attributes. How would you design the database schema for this scenario?
- Create separate tables for each product type
- Implement a superclass-subclass relationship with a product superclass and electronics/clothing subclasses
- Use a NoSQL database instead of a relational database
- Use a single table for all products with nullable columns for specific attributes
To design the database schema for this scenario, a superclass-subclass relationship with a product superclass and electronics/clothing subclasses is ideal. This allows common attributes like name and price to be stored in the superclass while specific attributes can be stored in the subclasses. It provides flexibility and scalability in the database design.
The _______ constraint ensures that a value in a column matches one of a set of predefined values.
- Check
- Default
- Foreign
- Unique
The Check constraint is used to ensure that a value in a column matches a specific condition or set of conditions, including predefined values. It helps in maintaining data accuracy and consistency within the database.
In document-based modeling, what is denormalization and how does it differ from normalization?
- It is the process of optimizing for both read and write operations, eliminating redundancy
- It is the process of optimizing for data storage, maximizing redundancy for reliability
- It is the process of optimizing for read operations, minimizing redundancy for consistency
- It is the process of optimizing for write operations, introducing redundancy for performance
Denormalization in document-based modeling involves introducing redundancy to optimize for write operations, improving performance by reducing the need for complex joins. This is in contrast to normalization, which aims to minimize redundancy for consistency and optimize for read operations.
Scenario: A team of data modelers is working on a project. They need to ensure that changes made by one team member do not conflict with changes made by another. Which feature of version control would be most helpful in this situation?
- Branching
- Check-in/check-out
- Merging
- Version tagging
In this scenario, the feature of version control that would be most helpful is "Branching." Branching allows team members to work on separate copies (branches) of the data model, making changes independently. Once changes are complete, they can be merged back into the main branch, minimizing conflicts.
Database design tools aid in maintaining _______ throughout the database development process.
- Data consistency
- Hardware performance
- System security
- User interface
Database design tools aid in maintaining data consistency throughout the database development process. Ensuring data consistency is crucial for accurate and reliable information storage and retrieval within the database, contributing to the overall integrity of the system.