Can a subclass have multiple superclasses in a Generalization and Specialization hierarchy? Explain.

  • No, a subclass can only have one superclass
  • No, multiple superclasses violate normalization principles
  • Yes, but it leads to data redundancy
  • Yes, through multiple inheritances
In a Generalization and Specialization hierarchy, a subclass can have multiple superclasses through multiple inheritances. However, this approach introduces complexities and potential issues like ambiguity and data redundancy.

Scenario: A multinational corporation requires a database design tool that can integrate with their existing software ecosystem, including enterprise resource planning (ERP) systems. They also need robust support for data security and compliance. Which database design tool would you suggest, and how does it meet the corporation's requirements?

  • IBM Data Architect
  • Microsoft SQL Server Management Studio (SSMS)
  • Oracle SQL Developer
  • SAP PowerDesigner
SAP PowerDesigner is recommended for its ability to integrate with enterprise software ecosystems, including ERP systems. It also provides robust support for data security and compliance, making it suitable for the stringent requirements of a multinational corporation.

In a Snowflake Schema, how are dimension tables organized?

  • Dimension tables are organized in a flat, denormalized structure
  • Dimension tables are organized in a hierarchical, normalized structure
  • Each dimension table is directly connected to the fact table
  • Fact table is organized in a snowflake pattern
In a Snowflake Schema, dimension tables are organized in a hierarchical, normalized structure. Unlike a Star Schema, where dimension tables are directly connected to the fact table, Snowflake Schema allows for a more normalized representation of data, reducing redundancy.

In NoSQL databases, _______ consistency model ensures that all updates are immediately visible to all clients.

  • Causal
  • Consistent
  • Eventual
  • Strong
In NoSQL databases, the Strong consistency model ensures that all updates are immediately visible to all clients. This means that once a write is acknowledged, all subsequent reads will reflect that update, providing a high level of consistency in the data.

What advantage does Microsoft Visio offer over other database design tools?

  • Integration with Microsoft Office applications
  • Limited support for different database systems
  • No collaboration features
  • Only supports small databases
Microsoft Visio offers an advantage with its integration with Microsoft Office applications. This allows users to seamlessly incorporate their database diagrams into other Office documents, fostering better communication and documentation. Its versatility makes it a preferred choice for those already using Microsoft tools.

Version control helps in managing _______ changes made to data models.

  • Incremental
  • Logical
  • Real-time
  • Structural
Version control facilitates the management of incremental changes made to data models over time. It tracks modifications, maintains a history of revisions, and enables collaboration while ensuring the integrity and consistency of the data modeling process.

Scenario: A social media platform needs to store user posts, comments, and likes. Each user can have millions of posts, comments, and likes associated with them. Which type of database would be most suitable for this scenario?

  • Graph Database
  • In-Memory Database
  • NoSQL Database
  • Relational Database
A NoSQL database would be most suitable for this scenario. NoSQL databases, especially document-oriented ones, are well-suited for handling large amounts of unstructured or semi-structured data, making them ideal for storing user-generated content like posts, comments, and likes in a social media platform.

What role does the replication factor play in maintaining data consistency in NoSQL databases?

  • Affecting read and write performance
  • Controlling data security
  • Determining data durability
  • Ensuring data availability
The replication factor in NoSQL databases plays a crucial role in maintaining data consistency by affecting read and write performance. A higher replication factor enhances data availability and fault tolerance but may introduce higher latency in write operations due to synchronization among replicas. It is a trade-off that administrators need to consider based on the desired level of consistency and performance.

In conceptual schema design, the emphasis is on __________ rather than implementation details.

  • Database normalization
  • High-level representation
  • Performance optimization
  • Query optimization
In conceptual schema design, the emphasis is on creating a high-level representation of the data model, focusing on the structure and relationships of entities. It abstracts away implementation details to capture the essence of the data.

Scenario: A social media platform stores user profiles, posts, and comments in separate tables. The platform is experiencing slow query performance when loading user feeds. How might denormalization help improve performance?

  • Create materialized views for user feeds
  • Implement sharding for distributed data storage
  • Introduce redundancy by combining tables to reduce JOIN operations
  • Normalize the tables to eliminate redundant data
Denormalization can improve performance in this scenario by introducing redundancy through the combination of tables, reducing the need for JOIN operations when loading user feeds. This helps streamline queries and enhance retrieval speed.

What are some common strategies for implementing superclass-subclass relationships in relational databases?

  • All of the above
  • Table-per-concrete-class
  • Table-per-hierarchy
  • Table-per-subclass
Common strategies for implementing superclass-subclass relationships in relational databases include Table-per-hierarchy, Table-per-subclass, and Table-per-concrete-class. Each strategy has its own advantages and considerations based on the specific requirements of the database model.

What is the difference between Type 1 and Type 2 Slowly Changing Dimensions (SCD)?

  • Creates a new record for each change
  • Deletes old records
  • Only updates the current record
  • Retains historical data in a separate table
The key difference between Type 1 and Type 2 SCD lies in handling changes. Type 1 updates the current record, overwriting old values, while Type 2 creates a new record for each change. This preserves historical data, allowing analysis of data changes over time.