Identify AWS Database Services

🗄️Exam Guide: Cloud Practitioner
Domain 3: Cloud Technology & Services
📘Task Statement 3.4

🎯 What Is This Task Testing?

You must recognize AWS database options and match them to scenarios:

• When to use Databases on EC2 vs Managed Databases
• Identify Relational services (Amazon RDS, Amazon Aurora)
• Identify NoSQL services (Amazon DynamoDB)
• Identify Memory-Based services (Amazon ElastiCache)
• Know Database Migration Tools (AWS DMS, AWS SCT)

1) 🧠 EC2-Hosted Databases vs Managed Databases

A common decision to make is whether you should run a database yourself on Amazon EC2 or use a managed database service.

Self Managed Databases on Amazon EC2

You install and manage the database software on EC2.

You Manage:

• OS and database patching
• backups and restores
• high availability setup
• scaling and maintenance tasks

Use Self Managed Databases on Amazon EC2 When:

• you need full control over the OS/database configuration
• you must use a database engine/configuration not supported by managed services
• you have special compliance or tooling requirements that require self-management

AWS Managed Databases

AWS handles many operational tasks.

Benefits When AWS Operates The Platform:

• reduced administrative overhead (patching, backups, maintenance)
• built-in high availability options
• easier scaling and monitoring
• faster time-to-value

Use AWS Managed Databases When:

• you want to offload routine database administration
• you want built-in reliability features without building everything yourself

2) 🧾Relational Databases

SQL

Relational databases are used when you need structured data, SQL queries, joins, and strong consistency/transaction support.

Amazon RDS

A managed service for relational databases and supports multiple engines.

Use Amazon RDS When:

• you want a managed relational database with common engines
• you need standard SQL database capabilities with simplified operations

“managed SQL database” → Amazon RDS.

Amazon Aurora

A relational database purpose built for the cloud and compatible with common SQL engines.

Use Amazon Aurora When:

• you want higher performance and cloud-optimized relational database features
• you want a managed relational database designed for scalability and availability

“cloud-optimized relational,” “high performance relational” → Amazon Aurora.

3) 🧩 NoSQL Databases

Amazon DynamoDB

A managed NoSQL database service designed for very fast, scalable access patterns.

Use Amazon DynamoDB When:

• you need low-latency reads/writes at scale
• your data model is key-value or document-style
• you want a fully managed NoSQL service without server management

“serverless NoSQL,” “key-value,” “massive scale with low latency” → DynamoDB.

4) ⚡ Memory-Based Databases

A managed in-memory data store commonly used for caching.

Use Amazon ElastiCache When:

• you need caching to reduce database load
• you need very fast access for frequently requested data
• you need in-memory storage for performance-sensitive workloads (like session storage, leaderboards, or caching query results)

“in-memory,” “cache,” “speed up reads” → ElastiCache.

5) 🚚 Database Migration Tools

Can you identify the right tool for moving Databases to AWS?

AWS Database Migration Service (AWS DMS)

AWS DMS is a service designed to move data between databases and it helps migrate databases to AWS with minimal downtime.

Use AWS DMS When:

• you need to migrate data from one database to another
• you want to reduce downtime during migration (continuous replication can be part of the approach)

“migrate with minimal downtime,” “replicate database to AWS” → AWS DMS.

AWS Schema Conversion Tool (AWS SCT)

AWS SCT helps convert database schemas and code when moving between database engines especially from commercial/legacy engines to AWS-supported targets.

Use AWS SCT When:

• the source and target database engines differ and require schema/code conversion
• you need help converting tables, indexes, stored procedures, etc.

“convert schema,” “move from one engine to another” → AWS SCT.

✅ Quick Exam-Style Summary

• EC2-hosted DB: maximum control, maximum operational responsibility.
• Managed DB: AWS reduces ops overhead (patching, backups, HA features).
• Relational (SQL): Amazon RDS, Amazon Aurora.
• NoSQL: Amazon DynamoDB.
• In-memory/caching: Amazon ElastiCache.
• Migration:
  • AWS DMS: migrate/replicate data (often minimal downtime)
  • AWS SCT: convert schema/code across engines

Additional Resources

Databases