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.
A financial institution needs to summarize transaction data by month to generate monthly reports. How would you implement this aggregation in a database?
- AVG() function
- GROUP BY with MONTH() function
- JOIN with a calendar table
- SUM() function
To summarize transaction data by month, you would use GROUP BY along with the MONTH() function to extract the month from the date column. This allows you to group transactions by month and generate the required monthly reports.
Which factor is NOT typically considered during storage optimization?
- Access patterns
- Data integrity
- Data redundancy
- Hardware configuration
Data redundancy is typically not considered during storage optimization because it refers to the repetition of data within a dataset. Storage optimization focuses on reducing storage space without compromising data integrity or accessibility based on factors such as access patterns and hardware configuration.
What is the purpose of a primary key in a relational database?
- Allows NULL values
- Defines data types
- Ensures data uniqueness
- Represents a foreign key
The primary key in a relational database serves the crucial role of ensuring data uniqueness within a table. It uniquely identifies each record, facilitating data integrity and providing a basis for relationships with other tables.
Conceptual schema design aims to create a high-level __________ of the database.
- Abstraction
- Blueprint
- Representation
- Structure
Conceptual schema design aims to create a high-level abstraction of the database. It provides a conceptual view that is independent of the specific database management system and focuses on the essential aspects of the data model.
Which UML diagram is typically used for modeling the relationships between objects?
- Activity Diagram
- Class Diagram
- Sequence Diagram
- Use Case Diagram
The Class Diagram is typically used for modeling the relationships between objects in UML. It represents the structure of classes and their associations, attributes, and operations. Class diagrams help visualize the static structure of a system and the relationships between different classes or objects.
How do Data Warehouses and Data Marts differ in terms of their intended audience and use cases?
- Data Marts are exclusively for data scientists
- Data Marts cater to departmental or team-level analytics
- Data Warehouses support enterprise-wide reporting and analysis
- Data Warehouses target executives and top-level management
Data Warehouses are designed for enterprise-wide reporting and analysis, targeting executives, and top-level management. In contrast, Data Marts focus on specific departments or teams, providing more specialized and focused analytics for smaller-scale needs.
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.
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.
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.
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.
Scenario: A university has departments and professors. Each department can have multiple professors, and a professor can belong to only one department. How would you represent this scenario in an Entity-Relationship Diagram (ERD)?
- Many-to-Many
- Many-to-One
- One-to-Many
- One-to-One
In this scenario, a One-to-Many relationship would be appropriate. Each department can have multiple professors (One-to-Many), but a professor can belong to only one department. This reflects the constraint that each professor is associated with a single department.