A company is implementing a new database system to store large volumes of transaction data. They are concerned about storage costs and data retrieval speed. What type of compression technique would you recommend for their system and why?

  • Dictionary-based Compression
  • Huffman Coding
  • Lossless Compression
  • Run-Length Encoding
For a database storing transaction data where data integrity is crucial, a lossless compression technique like Huffman Coding or Dictionary-based Compression is recommended. These methods reduce storage size without losing any data, ensuring accurate retrieval and maintaining the integrity of financial transactions.

What considerations should be taken into account when selecting a database design tool for a specific project?

  • Brand popularity, tool popularity, and available templates
  • Cost, scalability, user interface, team expertise, and integration capabilities
  • Project size, development speed, and community support
  • User reviews and software update frequency
Selecting a database design tool requires careful consideration of factors such as cost, scalability, user interface, team expertise, and integration capabilities. These aspects impact the overall success of the project and ensure that the chosen tool aligns with the specific needs and goals of the development team.

Scenario: A company's database experiences slow query performance during peak usage hours. What steps would you take to identify and address the performance issues?

  • Analyze and optimize SQL queries, implement indexing strategies, scale hardware resources, and consider database caching mechanisms
  • Monitor network bandwidth, increase database redundancy, partition tables, and implement query rate limiting
  • Optimize the application code, increase server clock speed, enable database replication, and add more indexes
  • Update the database software, restart the database server, archive old data, and implement load balancing
Slow query performance can be addressed by optimizing SQL queries, implementing proper indexing strategies, scaling hardware resources, and using database caching mechanisms. These steps help in identifying and resolving performance bottlenecks during peak hours.

The process of removing redundant data and ensuring data integrity in a database is known as _______.

  • Aggregation
  • Denormalization
  • Indexing
  • Normalization
The process described is known as Normalization. It involves organizing the database to minimize redundancy and dependency by dividing large tables into smaller ones and establishing relationships between them. This enhances data integrity and reduces the likelihood of anomalies.

How does generalization enhance the clarity and efficiency of a data model?

  • Increasing redundancy by duplicating attributes across entities
  • Limiting data abstraction to individual entities
  • Reducing redundancy by defining common characteristics in a superclass
  • Simplifying queries by creating complex relationships
Generalization enhances the clarity and efficiency of a data model by reducing redundancy. Common characteristics are defined in a superclass, and subclasses inherit these attributes, promoting a more organized and maintainable structure.

Scenario: A data analyst needs to query a database to extract specific information for a report. Would they likely use SQL or UML for this task, and why?

  • Both SQL and UML
  • No specific language needed
  • SQL
  • UML
A data analyst would likely use SQL (Structured Query Language) for querying a database to extract specific information for a report. SQL is specifically designed for interacting with databases, allowing the analyst to write queries to retrieve, filter, and manipulate data efficiently. UML, on the other hand, is a modeling language and is not intended for direct database querying.

What is the significance of the "column" in a column-family store?

  • It represents a data attribute
  • It represents a foreign key
  • It represents a primary key
  • It represents a record
In a column-family store, the "column" signifies a data attribute. Each column contains a specific piece of information, and rows may have varying columns based on the data they hold. This flexibility allows for dynamic and schema-less data storage, offering versatility in managing diverse datasets.

An _______ entity is one that represents a many-to-many relationship between two other entities.

  • Aggregated
  • Associative
  • Atomic
  • Derived
An associative entity is one that represents a many-to-many relationship between two other entities. It is introduced to resolve a many-to-many relationship by breaking it down into two one-to-many relationships, connecting the original entities through the associative entity.

Which type of consistency model ensures that all reads reflect the most recent write for a given data item in a distributed system?

  • Causal Consistency
  • Eventual Consistency
  • Strong Consistency
  • Weak Consistency
Strong Consistency ensures that all reads reflect the most recent write for a given data item in a distributed system. This model guarantees that any read operation will return the most recent write, providing a high level of data consistency but often at the cost of increased latency and reduced availability.

Star Schema often leads to _______ query performance compared to Snowflake Schema.

  • Better
  • Similar
  • Unpredictable
  • Worse
Star Schema often leads to Better query performance compared to Snowflake Schema. The denormalized structure of Star Schema simplifies query execution by minimizing joins, resulting in faster analytical query performance.

_______ is the process of reorganizing table and index data to improve query performance and reduce contention in a database.

  • Data Replication
  • Data Sharding
  • Database Partitioning
  • Database Tuning
Database Tuning is the process of reorganizing table and index data to enhance query performance and reduce contention in a database. It involves optimizing queries, indexing, and other database structures to achieve better efficiency.

Scenario: A financial institution needs to maintain a vast amount of transaction records while ensuring fast access to recent data. How would you implement partitioning to optimize data retrieval and storage?

  • Partitioning based on account numbers
  • Partitioning based on transaction dates
  • Partitioning based on transaction types
  • Randomized partitioning
Partitioning based on transaction dates is a recommended strategy in this scenario. It allows for segregating data based on time, making it easier to manage and retrieve recent transactions quickly. This enhances query performance and ensures that the most relevant data is readily accessible.