What is the primary data structure used in document-based modeling?
- Graph
- JSON
- Key-Value Pair
- Table
The primary data structure used in document-based modeling is JSON (JavaScript Object Notation). JSON allows for flexible and hierarchical data representation, making it suitable for storing and retrieving complex data structures. Document databases leverage this format to organize and query data efficiently.
What does a modality of "Optional" mean in a relationship?
- The relationship is mandatory for all entities involved
- The relationship is not necessary for the entities involved
- The relationship is optional for all entities involved
- The relationship is optional for one entity and mandatory for the other entity
In a relationship with a modality of "Optional," it means that the relationship is optional for all entities involved. This implies that an entity can exist without being associated with another entity through the specified relationship.
What strategies can be employed to optimize indexing for large-scale databases?
- Avoid indexing altogether for large-scale databases
- Choose appropriate column(s) for indexing
- Regularly rebuild all indexes
- Use fewer indexes to minimize overhead
Optimizing indexing for large-scale databases involves choosing appropriate columns for indexing, considering the query patterns. It's essential to strike a balance between query performance and maintenance overhead.
How does collaborative data modeling differ from individual data modeling?
- It focuses on creating data models for personal use only
- It has no impact on the overall data modeling process
- It involves multiple individuals working together on the same data model
- It uses different symbols in data modeling diagrams
Collaborative data modeling involves multiple individuals working together on the same data model, fostering teamwork and incorporating diverse perspectives. This approach enhances the quality and completeness of the data model compared to individual efforts.
In database performance tuning, _______ is the process of rearranging the way data is stored to improve query performance.
- Clustering
- Denormalization
- Partitioning
- Sharding
In database performance tuning, clustering is the process of rearranging the way data is stored to improve query performance. Clustering involves storing related data together physically on the disk, which can reduce disk I/O and improve query speed.
Scenario: A database has a table with attributes {EmployeeID, ProjectID, HoursWorked}. Is this table in the third normal form (3NF)?
- Cannot be determined
- No
- Not applicable
- Yes
Yes
What is the primary focus of Dimensional Modeling?
- Data Integrity
- Normalization
- Performance for retrieval and analysis
- Transaction processing
The primary focus of Dimensional Modeling is optimizing performance for retrieval and analysis. Unlike normalization, which aims for data integrity through minimizing redundancy, Dimensional Modeling prioritizes efficient querying and reporting for analytical purposes. This involves designing structures that align with how users typically access and analyze data in a data warehouse.
Which factor is typically NOT considered when deciding how to partition data?
- Data compression ratio
- Data distribution across servers
- Query performance requirements
- Security requirements
The data compression ratio is typically not considered when deciding how to partition data. Partitioning decisions are primarily based on factors such as data distribution, query performance, and security requirements, but compression considerations are addressed separately.
In Forward Engineering, the process starts with a _______ data model and progresses towards a detailed physical model.
- Abstract
- Conceptual
- Concrete
- Logical
In Forward Engineering, the process begins with a Logical Data Model. This model represents the abstract structure of the data without concerning itself with the physical implementation. It serves as a bridge between the high-level conceptual model and the detailed physical model.
Scenario: A hospital manages doctors, patients, and appointments. Each patient can have multiple appointments, each doctor can have multiple appointments, and each appointment is associated with one patient and one doctor. How would you represent this scenario in an ERD?
- Many-to-Many
- Many-to-One
- One-to-Many
- One-to-One
For this scenario, a One-to-One relationship is appropriate. Each appointment is associated with one patient and one doctor. It ensures that each appointment is uniquely linked to a specific patient and doctor, avoiding data redundancy.