MCQs on Performance Optimization Basics in Redshift | AWS Redshift Optimization Questions

AWS Redshift, a powerful cloud-based data warehousing solution, is essential for data analysts and engineers. This guide provides 30 AWS Redshift MCQs on Performance Optimization Basics, covering distribution styles, sort keys, query tuning, and workload monitoring. Test your knowledge with these expertly curated questions and find answers at the end for self-assessment.

Distribution Styles (Key, All, and Even)

1. What is the primary purpose of distribution styles in AWS Redshift?
   a) Improve data loading speed
   b) Optimize query performance
   c) Ensure data redundancy
   d) Simplify table creation
2. Which distribution style is best for a small lookup table?
   a) KEY
   b) ALL
   c) EVEN
   d) RANDOM
3. What determines the distribution style “KEY” in AWS Redshift?
   a) A predefined algorithm
   b) A user-defined column
   c) The sort key of the table
   d) The default table configuration
4. How does the EVEN distribution style allocate data?
   a) Based on the sort key
   b) Across all nodes evenly
   c) To a single node
   d) According to the cluster type
5. When is the ALL distribution style least effective?
   a) For small lookup tables
   b) For large, frequently updated tables
   c) For queries joining multiple tables
   d) When dealing with static data

Sort Keys: Types and Usage

6. What is the primary benefit of sort keys in AWS Redshift?
   a) Data encryption
   b) Query performance improvement
   c) Faster data loading
   d) Reduced storage costs
7. Which sort key is suitable for time-series data?
   a) Interleaved sort key
   b) Compound sort key
   c) Random sort key
   d) Hash sort key
8. How does a compound sort key work in AWS Redshift?
   a) Sorts data based on multiple columns in sequence
   b) Randomly distributes data across nodes
   c) Sorts data based on hash functions
   d) Automatically adjusts sorting during queries
9. What is a key limitation of interleaved sort keys?
   a) Increases query complexity
   b) Inefficient for single-column queries
   c) Higher maintenance overhead
   d) Requires specific compression settings
10. When is a compound sort key most beneficial?
    a) For tables with a high number of rows
    b) For queries filtering multiple columns in a specific order
    c) For joining multiple tables
    d) For time-series data

Basic Query Tuning

11. What does query tuning primarily aim to achieve in AWS Redshift?
    a) Minimize storage costs
    b) Optimize query performance
    c) Improve data availability
    d) Enhance user management
12. Which of the following is NOT a recommended query tuning strategy?
    a) Use SELECT * for queries
    b) Analyze and Vacuum tables regularly
    c) Use predicates with sort keys
    d) Limit the number of joins
13. How does “DISTKEY” impact query performance?
    a) Balances data evenly across nodes
    b) Reduces the need for data movement
    c) Improves data compression
    d) Simplifies query execution
14. What is the role of WLM in query tuning?
    a) Assign queries to specific nodes
    b) Allocate memory and CPU resources to queries
    c) Manage table distributions
    d) Monitor query duration
15. Which function is used to analyze query execution in AWS Redshift?
    a) ANALYZE QUERY
    b) EXPLAIN
    c) QUERY PLAN
    d) OPTIMIZE

Monitoring Workload Performance

16. What does AWS Redshift’s Workload Management (WLM) help to achieve?
    a) Secure data backups
    b) Manage cluster configurations
    c) Optimize query throughput
    d) Increase node capacity
17. Which metric is most relevant for monitoring query performance?
    a) Disk usage
    b) CPU utilization
    c) Query queue time
    d) Data replication rate
18. How does the “STL_QUERY” system table assist in performance monitoring?
    a) Tracks historical query data
    b) Configures table sort keys
    c) Displays cluster errors
    d) Analyzes table compression
19. What is the role of the “SVL_QLOG” system view?
    a) View running queries in real-time
    b) Display query queue lengths
    c) Analyze query performance trends
    d) Log user login events
20. Which tool provides a graphical interface for monitoring AWS Redshift performance?
    a) CloudWatch
    b) AWS Management Console
    c) Query Editor v2
    d) Performance Insights

Miscellaneous

21. Which AWS Redshift feature reduces storage for infrequently accessed data?
    a) Redshift Spectrum
    b) Enhanced VPC Routing
    c) Concurrency Scaling
    d) Cold Data Storage
22. What is the default number of query queues in AWS Redshift?
    a) 2
    b) 3
    c) 5
    d) 8
23. What does the “ANALYZE” command in AWS Redshift do?
    a) Update sort key configurations
    b) Reorganize data distribution
    c) Collect statistics for query optimization
    d) Compress table data
24. What does “VACUUM FULL” accomplish?
    a) Reclaims disk space and sorts rows
    b) Deletes all data from the table
    c) Moves data to a different cluster
    d) Updates query statistics
25. How does Redshift Spectrum enhance performance?
    a) Speeds up joins on distributed data
    b) Queries data stored in S3 without loading
    c) Optimizes sort key selection
    d) Enables parallel data replication

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