What is the time complexity of quicksort algorithm in the worst case?
Answer: B
Quicksort's worst-case complexity is O(n²) when pivot selection is poor, though average case is O(n log n).
Q.42Medium
In cloud computing, which service model allows customers to run their own applications but not manage infrastructure?
Answer: B
PaaS (Platform as a Service) provides a platform to develop and deploy applications without managing underlying infrastructure.
Q.43Medium
What is the difference between DELETE and TRUNCATE in SQL?
Answer: B
TRUNCATE is DDL (immediate, cannot be rolled back in most databases), DELETE is DML (slower, can be rolled back).
Q.44Medium
In graph algorithms, which algorithm finds the shortest path in weighted graphs?
Answer: C
Dijkstra's algorithm efficiently finds shortest paths from a source node to all other nodes in weighted graphs with non-negative weights.
Q.45Medium
What does normalization in machine learning context primarily aim to achieve?
Answer: B
Normalization scales features (e.g., 0-1 range) preventing features with larger scales from dominating model training.
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Q.46Medium
In cybersecurity, what is SQL injection attack?
Answer: B
SQL injection exploits vulnerable input handling to execute unintended SQL commands, potentially exposing or modifying data.
Q.47Medium
What is the primary difference between supervised and unsupervised machine learning?
Answer: A
Supervised learning trains on labeled data (features + targets); unsupervised finds patterns in unlabeled data without predefined outputs.
Q.48Medium
In database indexing, which type of index structure provides the best average-case performance for range queries in modern database systems?
Answer: B
B+ Tree indexes maintain sorted order and support efficient range queries, point queries, and prefix searches. Hash indexes are faster for exact matches but cannot handle range queries efficiently.
Q.49Medium
Which of the following SQL query optimization techniques is most effective when dealing with large fact tables in a data warehouse environment?
Answer: B
Data warehouses use materialized views to pre-aggregate data and strategic denormalization for faster analytical queries. These techniques significantly improve performance on large fact tables.
Q.50Medium
In the context of distributed databases, which consistency model is used by most cloud-native databases like DynamoDB and offers eventual consistency?
Answer: C
Cloud-native NoSQL databases prioritize availability and partition tolerance (CAP theorem), implementing eventual consistency to handle distributed system challenges while maintaining horizontal scalability.
