AWS Certified Solutions Architect - Associate

Explanation

Correct Answer: C - Create a read replica of the primary database and have the business analysts run their queries.

Why Option C is Correct:

1. Minimal Changes to Existing Application: Creating a read replica requires minimal changes to the existing web application. The business analysts can be redirected to query the read replica instead of the primary database, while the main application continues to use the primary database for write operations.

2. Offloads Read Queries: Read replicas in Amazon RDS are specifically designed to handle read-only queries, which offloads the read workload from the primary database instance. This directly addresses the performance degradation caused by increased read-only queries.

3. Maintains Data Consistency: Read replicas asynchronously replicate data from the primary database, ensuring that business analysts get relatively current data for their analytical queries.

4. Cost-Effective Solution: Read replicas are typically less expensive than creating entirely new database solutions and maintain the same SQL interface that business analysts are already familiar with.

Why Other Options Are Incorrect:

Option A (Export to DynamoDB):

• DynamoDB is a NoSQL database with a different query model
• Would require significant application changes and data transformation
• Business analysts would need to learn a new query language (DynamoDB Query/Scan API)

Option B (Load into ElastiCache):

• ElastiCache is an in-memory caching service, not designed for complex analytical queries
• Limited query capabilities compared to SQL databases
• Not suitable for ad-hoc business intelligence queries

Option D (Copy to Redshift):

• Redshift is a data warehouse optimized for analytical queries, but:
• Requires ETL processes to move data
• Would create data latency issues
• Business analysts would need to learn Redshift-specific SQL extensions
• More complex and costly than a simple read replica

Key AWS Concepts:

• Amazon RDS Read Replicas: Provide enhanced performance and durability for read-heavy database workloads
• Read/Write Splitting: A common pattern where write operations go to the primary database and read operations go to read replicas
• Asynchronous Replication: Read replicas use asynchronous replication, which means there might be some replication lag, but this is acceptable for most analytical workloads

This solution directly addresses the performance degradation while maintaining the existing application architecture with minimal changes.