AWS AWS Database Services 1 — Questions and Answers
Question 1: When should you choose Amazon DynamoDB over Amazon RDS?
- For applications needing single-digit millisecond latency at any scale with flexible schema (Correct answer)
- For applications requiring complex SQL joins
- For traditional relational workloads with ACID transactions
- Only for static website hosting
Correct answer: For applications needing single-digit millisecond latency at any scale with flexible schema
DynamoDB is ideal for applications requiring consistent single-digit millisecond performance at any scale, flexible schemas, and key-value or document data models, while RDS suits traditional relational workloads with complex queries.
Question 2: What is Amazon Aurora and how does it differ from standard RDS?
- A MySQL/PostgreSQL-compatible database with up to 5x and 3x better performance respectively and automatic storage scaling (Correct answer)
- A data warehouse service
- A caching service similar to ElastiCache
- An in-memory database only
Correct answer: A MySQL/PostgreSQL-compatible database with up to 5x and 3x better performance respectively and automatic storage scaling
Aurora is AWS's proprietary cloud-optimized relational database offering MySQL and PostgreSQL compatibility with superior performance, automatic storage scaling up to 128 TB, and up to 15 read replicas.
Question 3: What is Amazon ElastiCache and when should it be used?
- A managed in-memory caching service (Redis or Memcached) for reducing database load and improving latency (Correct answer)
- A service for caching S3 objects on disk
- A CDN for API responses
- A database backup service
Correct answer: A managed in-memory caching service (Redis or Memcached) for reducing database load and improving latency
ElastiCache provides managed Redis or Memcached in-memory caching, used to reduce database read load, store session data, cache API responses, and improve application latency for frequently accessed data.
Question 4: What is Amazon Redshift used for?
- A fully managed data warehouse for analyzing large datasets using SQL (Correct answer)
- A tool for shifting data between regions
- A service for real-time transaction processing
- A NoSQL database for document storage
Correct answer: A fully managed data warehouse for analyzing large datasets using SQL
Amazon Redshift is a fully managed, petabyte-scale data warehouse that uses columnar storage, massively parallel processing, and SQL-based analytics for business intelligence and big data analytics workloads.
Question 5: What is Amazon DocumentDB?
- A managed document database service compatible with MongoDB workloads (Correct answer)
- A service for storing PDF documents
- A text editor in the cloud
- An OCR scanning service
Correct answer: A managed document database service compatible with MongoDB workloads
Amazon DocumentDB is a fully managed document database service designed for MongoDB compatibility, providing scalable, highly available document storage with automatic backups, encryption, and replication.
Question 6: What is the purpose of Amazon DynamoDB Streams?
- To capture time-ordered sequences of item-level changes in a DynamoDB table for event-driven processing (Correct answer)
- To stream video content from DynamoDB
- To migrate data between DynamoDB tables
- To visualize DynamoDB table structure
Correct answer: To capture time-ordered sequences of item-level changes in a DynamoDB table for event-driven processing
DynamoDB Streams captures item-level modifications (inserts, updates, deletes) in near-real-time, enabling event-driven architectures, cross-region replication, and maintaining materialized views or search indexes.
AWS AWS Database Services 1
When should you choose Amazon DynamoDB over Amazon RDS?