In an Entity-Relationship Diagram, a _______ attribute is one that can be derived from other attributes.
- Composite
- Derived
- Key
- Multivalued
In an ERD, a Derived attribute is one that can be derived or calculated from other attributes in the database. It doesn't store data physically but can be computed based on other attribute values.
Scenario: A company has employees and departments. Each employee must be assigned to one department, but a department can have multiple employees. What cardinality and modality does this scenario represent?
- Many-to-Many, Optional
- Many-to-One, Mandatory
- One-to-Many, Mandatory
- One-to-One, Optional
This scenario represents a One-to-Many relationship with mandatory modality. Each department can have multiple employees (Many), while each employee must be assigned to one department (One). The modality is mandatory because every employee must be assigned to a department.
What factors are considered when deciding on the clustering key for a database table?
- Backup and recovery strategies
- Data distribution, query patterns, and join operations
- Primary key constraints, foreign key constraints, and unique constraints
- Table size, data types, and column names
Deciding on the clustering key involves considering factors like data distribution, query patterns, and join operations. A well-chosen clustering key can significantly impact query performance and overall database efficiency.
The process of converting a high-level conceptual model into a detailed logical model involves _______.
- Abstraction
- Aggregation
- Indexing
- Normalization
The process of converting a high-level conceptual model into a detailed logical model involves normalization. Normalization is the systematic organization of data to reduce redundancy and dependency, ensuring data integrity and efficiency in the database structure.
What is the primary goal of storage optimization in database systems?
- Improving query performance
- Increasing storage space
- Maximizing data redundancy
- Minimizing data integrity
The primary goal of storage optimization in database systems is to improve query performance. By optimizing how data is stored and accessed, database systems can process queries more efficiently, resulting in faster response times and better overall performance for users and applications accessing the database.
Graph databases provide native support for _______ operations, allowing efficient querying of connected data.
- Aggregation
- Indexing
- Sorting
- Traversal
Graph databases provide native support for traversal operations, allowing efficient querying of connected data. Traversal involves navigating through nodes and relationships in a graph to discover patterns or retrieve specific information, which is a key feature in graph databases.
A degenerate dimension in a fact table does not have a corresponding _______ table.
- Dimension
- Lookup
- Master
- Reference
A degenerate dimension in a fact table does not have a corresponding dimension table. Instead, the dimension attributes are stored directly in the fact table. This is suitable when the dimension has no significant details other than its key and is not reused across multiple facts.
What is the significance of storage optimization in relational schema design?
- Enhancing query performance
- Maximizing indexing
- Minimizing disk space usage
- Normalizing data
Storage optimization in relational schema design focuses on enhancing query performance by organizing and storing data efficiently. It involves strategies like indexing, partitioning, and denormalization to ensure quick and effective data retrieval.
How does compression affect data retrieval speed in a database system?
- Depends on the type of compression used
- Has no impact on retrieval speed
- Improves retrieval speed
- Slows down retrieval speed
Compression typically has no impact or can even improve data retrieval speed in a database system. By reducing the amount of data that needs to be transferred, it can enhance overall performance. However, the specific impact depends on the type of compression algorithm used and the characteristics of the data.
What is a potential drawback of partitioning a database?
- Complex administration and maintenance
- Increased query performance
- Increased storage space utilization
- Simplified data management
A potential drawback of partitioning a database is the complexity in administration and maintenance. While partitioning can enhance performance and simplify certain operations, managing and maintaining partitions can become complex, especially as the database scales. This requires careful planning and monitoring.