Databases

Question 1

A company runs an e-commerce application with unpredictable traffic spikes. The MySQL RDS database experiences high read load that degrades performance during sales. Which solution improves read performance with LEAST operational overhead?

Accepted Answer

Create multiple Read Replicas and distribute read traffic

Answer

Increase RDS instance size to the largest available class

Answer

Migrate to a db.t4g.micro instance with burstable performance

Answer

Enable Multi-AZ to distribute reads across AZs

Question 2

A critical application requires a database with RPO (Recovery Point Objective) less than 1 minute and RTO (Recovery Time Objective) less than 2 minutes. Which RDS configuration meets these requirements?

Accepted Answer

RDS Multi-AZ with synchronous replication

Answer

RDS Single-AZ with daily automated backups

Answer

RDS with Read Replica in another region

Answer

RDS with manual snapshots every hour

Question 3

An architect needs to design a database for a global application with users in America, Europe, and Asia. The application requires read latencies under 100ms in all regions. Which solution meets this requirement with HIGHEST performance and LOWEST latency?

Accepted Answer

Aurora Global Database with read replicas in multiple regions

Answer

RDS MySQL with Read Replicas in each region

Answer

DynamoDB with DAX in each region

Answer

Redshift with snapshot copies in each region

Question 4

A startup with variable traffic needs a MySQL-compatible database without managing capacity or paying for idle resources. Which option provides the best cost-benefit ratio?

Accepted Answer

Aurora Serverless v2 with automatic auto-scaling

Answer

RDS MySQL with Reserved Instances to reduce costs

Answer

EC2 with MySQL manually installed

Answer

Aurora Provisioned with minimal db.t3.small instance

Question 5

A web application needs to store user sessions with high read/write speed. Sessions automatically expire after 1 hour of inactivity. Which solution provides the LOWEST latency with automatic expiration?

Accepted Answer

ElastiCache Redis with key expiration policies

Answer

DynamoDB with TTL enabled on session items

Answer

RDS PostgreSQL with indexes on session timestamp

Answer

Aurora with stored procedures for session cleanup

Question 6

An IoT application ingests 50,000 events per second that must be stored with low latency. Access patterns are unpredictable and queries vary. Which characteristics should the solution have? (Select TWO)

Accepted Answer

Answer

Automatic scaling without predefined throughput limits

Answer

NoSQL data model with efficient partition keys

Answer

Requires defining relational schema before inserting data

Answer

Support for flexible secondary indexes

Answer

Needs manual IOPS capacity provisioning

Question 7

An analytics team needs to run complex queries on petabytes of historical data stored in S3 without moving the data. Which service enables this with HIGHEST speed and LOWEST operational complexity?

Accepted Answer

Redshift Spectrum to query S3 directly

Answer

Aurora with S3 integration to load data

Answer

EMR with Spark to process S3 files

Answer

Athena with optimized partitions

Question 8

A DynamoDB application experiences throttling during unpredictable traffic spikes. The team wants to avoid over-provisioning capacity. Which solution best balances cost and performance?

Accepted Answer

Switch to On-Demand mode with pay-per-request

Answer

Increase provisioned RCU and WCU to expected maximum

Answer

Enable Auto Scaling in Provisioned mode

Answer

Implement exponential backoff in the application

Question 9

A company needs to migrate an on-premises MongoDB application to AWS with minimal code changes and full MongoDB driver compatibility. Which service is MOST SUITABLE with LOWEST management overhead?

Accepted Answer

Amazon DocumentDB (with MongoDB compatibility)

Answer

DynamoDB with MongoDB compatibility adapter

Answer

EC2 with MongoDB Community Edition installed

Answer

RDS with NoSQL extension enabled

Question 10

A social media application needs to store complex relationships between users (friends, followers, interests) and run traversal queries like 'friends of friends'. Which database is optimal for this case?

Accepted Answer

Amazon Neptune with property graph model

Answer

DynamoDB with GSI indexes for relationships

Answer

RDS MySQL with multiple junction tables

Answer

DocumentDB with nested references