Scenario: An e-commerce platform needs to store product information, including images, descriptions, and pricing details. The platform wants to scale seamlessly as the number of products increases. Which database model would best suit this requirement and why?

  • Columnar Database
  • NoSQL Database
  • Object-Oriented Database
  • Relational Database
A NoSQL Database would be the best fit for this scenario. NoSQL databases, especially those designed for document storage, provide scalability and flexibility for handling diverse product information. The ability to store and retrieve complex data, including images and descriptions, aligns well with the requirements of an e-commerce platform.

In Dimensional Modeling, a _______ table contains descriptive attributes used for analysis.

  • Dimension
  • Fact
  • Lookup
  • Reference
In Dimensional Modeling, a Dimension table contains descriptive attributes used for analysis. These attributes provide context and additional information about the measures in the Fact table. For example, in a sales data warehouse, a Date Dimension table might contain attributes like year, quarter, and month.

In a Key-Value Store, the _______ is used to uniquely identify each value.

  • Index
  • Key
  • Key
  • Value
In a Key-Value Store, the Key is used to uniquely identify each value. The key serves as a unique identifier that allows efficient retrieval of the associated value. This simplicity is one of the key advantages of Key-Value Stores.

How does data redundancy compare between a Star Schema and a Snowflake Schema?

  • Both schemas have equal data redundancy
  • Data redundancy is not applicable to either schema
  • Snowflake Schema has higher data redundancy
  • Star Schema has higher data redundancy
Snowflake Schema typically has higher data redundancy compared to a Star Schema. In a Snowflake Schema, data is normalized into multiple tables, resulting in more duplicate data across different tables. In contrast, a Star Schema denormalizes data into a single table for each dimension, reducing redundancy.

In a distributed Key-Value Store, _______ is crucial for ensuring data availability and fault tolerance.

  • Consistency
  • Encryption
  • Replication
  • Sharding
In a distributed Key-Value Store, replication is crucial for ensuring data availability and fault tolerance. By storing multiple copies of data across different nodes, the system can continue to function even if some nodes fail, ensuring high availability and resilience against faults.

_______ analysis is a technique used in database performance tuning to identify and resolve performance bottlenecks.

  • Execution
  • Index
  • Profiling
  • Query
Performance profiling is a technique used in database performance tuning to analyze and identify bottlenecks in the system. It involves monitoring and measuring various aspects of the database, such as query execution times, resource usage, and query plans. Profiling helps in understanding where the performance issues lie and allows for targeted optimizations to improve overall system performance.

_______ compression reduces the storage size of data without losing any information.

  • Decompression
  • Encryption
  • Lossless
  • Lossy
Lossless compression reduces the storage size of data without losing any information. It is commonly used when it's important to preserve all the original data, such as in databases or text files. Unlike lossy compression, there is no loss of quality in the compressed data.

In a fact table, each record represents a _______ at a specific level of detail.

  • Entity
  • Event
  • Relationship
  • Transaction
In a fact table, each record represents a transaction at a specific level of detail. A fact table contains quantitative data, such as measurements or metrics, and is typically associated with a timestamp to capture when the transaction occurred. This helps in analyzing and understanding the details of specific events or transactions in the dataset.

Scenario: A university has staff members who can be either professors or administrative staff. How would you model this scenario using superclass and subclass relationships?

  • Create separate databases for professors and administrative staff
  • Create separate tables for professors and administrative staff
  • Use a single table for all staff members
  • Use a superclass-subclass relationship with a staff superclass and professor/administrative staff subclasses
In this scenario, the best approach is to use a superclass-subclass relationship. By having a staff superclass and professor/administrative staff subclasses, you can inherit common attributes from the superclass while allowing specific attributes for each subclass. This promotes data integrity and reduces redundancy.

Scenario: A financial institution aims to analyze customer transactions, account balances, and demographics. Considering the complexity of their queries, which schema would be more appropriate: Star Schema or Snowflake Schema?

  • Snowflake Schema, because it provides better data integrity and scalability for financial data analysis.
  • Snowflake Schema, because it supports more intricate relationships among financial data entities and enables better data normalization.
  • Star Schema, because it reduces the need for joins and simplifies data retrieval in financial analytics.
  • Star Schema, because it simplifies query complexity and enhances performance for analytical tasks.
For a financial institution analyzing complex customer data, Snowflake Schema may be more appropriate. Snowflake Schema's normalization reduces redundancy and ensures data integrity, crucial in financial operations where accuracy is vital. It accommodates intricate relationships among entities like customers, transactions, and demographics, facilitating comprehensive analysis and reporting.