Fundamentals of Redis and In-Memory Databases Quiz

1. Basic Concept

   Which main feature distinguishes an in-memory database from a traditional disk-based database?

   1. Data is primarily stored in RAM
   2. Data is only accessible through spreadsheets
   3. Requires hardware encryption
   4. Data is split into multiple servers automatically
   5. Supports only single-user access

2. Common Use Cases

   What is a typical scenario where an in-memory database like Redis is preferred?

   1. Storing frequently changing leaderboard scores in a gaming application
   2. Archiving old payroll records for long-term compliance
   3. Backing up all corporate data
   4. Storing large media files for streaming
   5. Maintaining paper document records

3. Data Types

   Which of the following is a built-in data structure supported by Redis?

   1. Sets
   2. Documents
   3. Records
   4. Graphs
   5. Sheets

4. Performance Advantage

   Why are in-memory databases usually faster than disk-based databases for read and write operations?

   1. RAM access times are much lower than disk access times
   2. They use larger display screens
   3. They compress data before reading
   4. They always transmit data over the internet
   5. They require more user passwords

5. Persistence

   Which statement best describes Redis's approach to data persistence?

   1. It can optionally save data to disk to recover after a restart
   2. It never provides any way to save data
   3. Data is always erased after every operation
   4. It only supports retention for one day
   5. Persistence requires external tools only

6. Key-Value Model

   In Redis, how is information typically stored?

   1. As key-value pairs
   2. In sequential tables
   3. As fixed-length arrays
   4. Within XML documents
   5. By color-coded folders

7. Atomicity

   When a command like INCR is used in Redis to increment a value, what property is guaranteed?

   1. The operation is atomic
   2. The operation is multilingual
   3. Updates happen once per week
   4. The value is always doubled
   5. Access is blocked for all users

8. Cache Use

   How can Redis be used as a cache in a web application?

   1. By temporarily storing frequently accessed data for faster retrieval
   2. By encrypting user passwords before storage
   3. By generating random user locations
   4. By storing only email messages
   5. By deleting data every minute

9. Data Expiry

   Which Redis feature allows automatic deletion of data after a specified period, such as when storing user session tokens?

   1. Expiration time (TTL)
   2. Dual locking
   3. Recursive resets
   4. Color tagging
   5. Mirrored sessions

10. Command Syntax

    Which of the following commands sets a value called 'fruit' to 'apple' in Redis?

    1. SET fruit apple
    2. PUT fruit=apple
    3. ADD (fruit, apple)
    4. INSERT apple INTO fruit
    5. VALUE fruit: apple