Cyber Intelligence
Cloud Technology and Services · 34% of exam

L12. Databases: RDS, DynamoDB, ElastiCache, and Aurora

Video generating

Check back soon for the video lesson on Databases: RDS, DynamoDB, ElastiCache, and Aurora

AWS offers managed relational and NoSQL databases. The Cloud Practitioner exam tests Amazon RDS, Aurora, DynamoDB, ElastiCache, and Redshift with their use cases and key differentiators.

Amazon RDS (Relational Database Service)

RDS is a managed relational database service supporting: MySQL, PostgreSQL, MariaDB, Oracle, SQL Server, and Amazon Aurora. What AWS manages: hardware, OS patching, database software patching, automated backups, Multi-AZ failover. What you manage: database schema, performance tuning, query optimization, access credentials. Multi-AZ deployments: RDS automatically replicates to a standby in a second AZ; failover happens automatically. Read Replicas: asynchronous read-only copies that offload read traffic; available in same Region or cross-Region.

Amazon Aurora

Aurora is AWS's proprietary relational database engine that is cloud-optimized for higher performance and availability than standard MySQL/PostgreSQL. Key facts:

  • Delivers up to 5x better throughput than MySQL and 3x better than PostgreSQL
  • Storage auto-scales from 10 GB to 128 TB
  • 6 copies of data across 3 AZs (built-in redundancy)
  • Aurora Serverless: auto-scales capacity to zero when idle; pay per second of use

Amazon DynamoDB

DynamoDB is a fully managed serverless NoSQL key-value and document database. Key characteristics:

  • Single-digit millisecond performance at any scale
  • No servers to manage; AWS handles all capacity, replication, and availability
  • DynamoDB Accelerator (DAX): in-memory cache for DynamoDB delivering microsecond latency

Amazon ElastiCache

ElastiCache is a managed in-memory caching service based on Redis or Memcached. Use cases: cache database query results, session management, real-time leaderboards.

Amazon Redshift

Redshift is a managed petabyte-scale data warehouse for analytics (OLAP workloads). Use when: running complex analytical queries across large datasets; not for transactional (OLTP) workloads.

Amazon Neptune

Neptune is a fully managed graph database for highly connected datasets (social networks, fraud detection, recommendation engines).

Database Selection Guide

WorkloadBest Service
Relational OLTPRDS or Aurora
NoSQL key-valueDynamoDB
In-memory cachingElastiCache
Data warehouse analyticsRedshift
Graph relationshipsNeptune
Exam tip: DynamoDB = NoSQL, serverless, millisecond latency. Aurora = high-performance relational, cloud-native. Redshift = analytics/BI, not OLTP.

Exam Focus Points
  • RDS is managed relational DB; AWS patches OS and DB engine; you manage schema and queries
  • Aurora is cloud-optimized MySQL/PostgreSQL with 5x MySQL throughput and automatic 6-copy replication across 3 AZs
  • DynamoDB is fully managed serverless NoSQL with single-digit millisecond performance at any scale
  • ElastiCache (Redis/Memcached) is in-memory caching to reduce database latency
  • Redshift is a managed petabyte-scale data warehouse for analytics, not transactional workloads
Knowledge Check

1. A company needs a database that can handle millions of requests per second with single-digit millisecond latency and does not require managing servers. Which AWS service is most appropriate?

2. Which Amazon RDS feature automatically replicates a database to a standby instance in a different Availability Zone and fails over automatically?

Recommended: Pluralsight

Complement these lessons with Pluralsight: structured CLF-C02 learning paths, AWS hands-on labs, and realistic practice questions for exam day.

Start CLF-C02 prep free10-day free trial available