Data Processing Data Storage and Retrieval 1 — Questions and Answers
Question 1: What is the difference between structured and unstructured data?
- Structured data is organized in predefined formats like tables; unstructured data has no predefined format (Correct answer)
- Structured data is stored on hard drives; unstructured data is stored in the cloud
- Structured data is always numeric; unstructured data is always text
- Structured data is encrypted; unstructured data is not
Correct answer: Structured data is organized in predefined formats like tables; unstructured data has no predefined format
Structured data conforms to a predefined schema (like rows in a database), while unstructured data lacks a formal structure (like emails, images, or video files).
Question 2: What is a data warehouse's key characteristic compared to an operational database?
- It is optimized for read-heavy analytical queries rather than transactional write operations (Correct answer)
- It only stores real-time streaming data
- It is updated continuously every millisecond
- It is always stored on a single machine for simplicity
Correct answer: It is optimized for read-heavy analytical queries rather than transactional write operations
Data warehouses are designed for OLAP (Online Analytical Processing), optimizing complex read queries across large historical datasets, unlike OLTP databases built for fast transactional writes.
Question 3: What does CRUD stand for in data management?
- Create, Read, Update, Delete (Correct answer)
- Compress, Retrieve, Upload, Download
- Copy, Restore, Undo, Deploy
- Cache, Replicate, Update, Deduplicate
Correct answer: Create, Read, Update, Delete
CRUD represents the four basic operations for persistent data storage: Create (insert), Read (query), Update (modify), and Delete (remove).
Question 4: What is the purpose of database caching?
- Storing frequently accessed data in fast memory to reduce retrieval time (Correct answer)
- Creating backup copies of the entire database
- Encrypting data before writing it to disk
- Sorting query results before returning them
Correct answer: Storing frequently accessed data in fast memory to reduce retrieval time
Database caching stores query results or frequently accessed data in fast in-memory storage, dramatically reducing database load and response times for repeated requests.
Question 5: What is a columnar storage format?
- Data stored column by column rather than row by row, optimized for analytical queries (Correct answer)
- A format that stores only text in database columns
- A way to encrypt each column separately for security
- A method of sorting rows by column values before storage
Correct answer: Data stored column by column rather than row by row, optimized for analytical queries
Columnar storage organizes data by columns rather than rows, allowing analytical queries to read only the columns they need rather than entire rows.
Question 6: What is an object storage system?
- A storage architecture that manages data as discrete objects with metadata rather than file hierarchies (Correct answer)
- A database that only stores JavaScript objects
- A type of RAID storage configuration
- A method for compressing binary data during storage
Correct answer: A storage architecture that manages data as discrete objects with metadata rather than file hierarchies
Object storage manages data as flat objects each with unique identifiers and metadata, making it ideal for storing massive amounts of unstructured data like images and videos.
Data Processing Data Storage and Retrieval 1
What is the difference between structured and unstructured data?