Data Processing Data Storage and Retrieval 2 — Questions and Answers
Question 1: What is RAID in the context of data storage?
- Redundant Array of Independent Disks — a method of combining multiple drives for redundancy or performance (Correct answer)
- Real-time Automated Indexing Daemon for fast data retrieval
- Remote Access Integrated Database for distributed systems
- Replicated Archive for Indexed Data storage
Correct answer: Redundant Array of Independent Disks — a method of combining multiple drives for redundancy or performance
RAID (Redundant Array of Independent Disks) combines multiple physical drives to improve data redundancy, fault tolerance, or read/write performance depending on the RAID level.
Question 2: What is the purpose of data archiving?
- Moving infrequently accessed data to lower-cost storage for long-term retention (Correct answer)
- Deleting old data to free up disk space
- Encrypting production data for compliance
- Compressing active databases during business hours
Correct answer: Moving infrequently accessed data to lower-cost storage for long-term retention
Data archiving moves historical or rarely accessed data from primary storage to cheaper long-term storage, reducing costs while preserving data for compliance or future reference.
Question 3: What is a B-tree index?
- A balanced tree data structure used by databases to enable fast data lookups and range queries (Correct answer)
- A binary backup format for database tables
- A branching diagram showing database relationships
- A compressed storage format for text data
Correct answer: A balanced tree data structure used by databases to enable fast data lookups and range queries
A B-tree (balanced tree) index is the most common database index structure, maintaining sorted data in a self-balancing tree that enables O(log n) lookups and efficient range scans.
Question 4: What does 'data tiering' mean in storage management?
- Automatically moving data between different storage classes based on access frequency and cost (Correct answer)
- Organizing database tables into logical groups by department
- Encrypting data at multiple security levels
- Creating multiple backups in different geographic locations
Correct answer: Automatically moving data between different storage classes based on access frequency and cost
Data tiering moves data across storage tiers — hot (fast/expensive SSD), warm (standard), and cold (cheap/slow) — based on how frequently it is accessed, optimizing cost and performance.
Question 5: What is a hash index in database storage?
- An index that uses a hash function to map keys directly to storage locations for O(1) equality lookups (Correct answer)
- An index sorted alphabetically by hash values
- A compressed index used only for text search
- An index that stores only the last 10% of rows in a table
Correct answer: An index that uses a hash function to map keys directly to storage locations for O(1) equality lookups
A hash index applies a hash function to key values to compute direct storage addresses, enabling extremely fast equality lookups but not supporting range queries.
Question 6: What is eventual consistency in distributed data storage?
- A model where all replicas will eventually converge to the same value given no new updates (Correct answer)
- A guarantee that all replicas are always identical at every moment
- A storage strategy that prioritizes speed over durability
- A backup policy that runs nightly to sync all nodes
Correct answer: A model where all replicas will eventually converge to the same value given no new updates
Eventual consistency guarantees that if no new writes occur, all replicas of a distributed data store will eventually return the same value, trading immediate consistency for availability.
Data Processing Data Storage and Retrieval 2
What is RAID in the context of data storage?