Choosing the Right AWS Database
AWS offers a broad range of purpose-built databases for different data models:
| Data Type / Use Case | Recommended Service |
|---|---|
| Relational (OLTP) | Amazon RDS, Aurora |
| Relational (serverless, cloud-native) | Aurora Serverless |
| Key-value / NoSQL | DynamoDB |
| In-memory caching | ElastiCache (Redis/Memcached) |
| Document store | Amazon DocumentDB |
| Graph data | Amazon Neptune |
| Time-series data | Amazon Timestream |
| Ledger (immutable logs) | Amazon QLDB |
| Wide-column (Cassandra) | Amazon Keyspaces |
| Object storage (data lake) | Amazon S3 |
📚 Database Types in AWS
| Type | Services |
|---|---|
| Relational | RDS (MySQL, PostgreSQL, SQL Server, Oracle, MariaDB), Aurora |
| Key-Value | DynamoDB |
| Document | DocumentDB, DynamoDB |
| Graph | Neptune |
| Time-Series | Timestream |
| Ledger | QLDB |
| In-Memory | ElastiCache (Redis, Memcached) |
| Wide-column | Amazon Keyspaces (Cassandra) |
| Object | S3 |
Amazon RDS – Summary
- Managed relational database service
- Supports: MySQL, PostgreSQL, SQL Server, MariaDB, Oracle
- Handles:
- Backups
- Patch management
- Failover (Multi-AZ)
- Read Replicas
✅ Ideal for existing SQL apps with minimal refactoring
Amazon Aurora – Summary
- AWS-built cloud-native relational database
- Compatible with MySQL & PostgreSQL
- 5x faster than MySQL, 3x than PostgreSQL
- Features:
- Auto-scaling
- Serverless option (v2)
- Global database
- Fault-tolerant storage
✅ Best for modern apps needing high performance
Amazon ElastiCache – Summary
- In-memory data store for caching and real-time analytics
- Engines:
- Redis (pub/sub, streams, persistence, cluster mode)
- Memcached (simple key-value cache)
- Ultra-low latency (sub-millisecond)
✅ Ideal for session storage, leaderboard, caching DB queries
Amazon DynamoDB – Summary
- Fully managed NoSQL key-value & document DB
- Millisecond latency, scalable to millions of requests/sec
- Features:
- On-demand or provisioned capacity
- TTL, Streams, Global Tables
- DynamoDB Accelerator (DAX)
✅ Best for serverless applications and high-throughput APIs
Amazon S3 – Summary
- Object storage service
- Not a database, but used in data lakes, backups, big data
- Features:
- Versioning
- Lifecycle policies
- Query support (Athena, S3 Select)
- Event triggers (S3 → Lambda/SNS/SQS)
✅ Often used with Glue, Athena, Redshift, EMR in analytics pipelines
Amazon DocumentDB – Summary
- Managed document database compatible with MongoDB
- Features:
- Replica sets, backups
- Change streams
- Scalability up to 64 TB per cluster
✅ Use for JSON-based applications using MongoDB drivers
Amazon Neptune – Summary
- Graph database service
- Supports:
- Property graph model (Gremlin)
- RDF graph model (SPARQL)
- Use cases:
- Social graphs
- Recommendation engines
- Fraud detection
✅ Choose Neptune when relationships are the focus
Amazon Keyspaces (for Apache Cassandra) – Summary
- Managed Cassandra-compatible database
- Scalable, fault-tolerant, serverless
- CQL (Cassandra Query Language) support
✅ Use for apps already using Cassandra
Amazon QLDB (Quantum Ledger Database) – Summary
- Immutable, cryptographically verifiable ledger
- Fully managed, serverless
- Great for:
- Audit trails
- Financial transactions
- Supply chain systems
✅ Choose QLDB for ledger-style applications with tamper-proof history
Amazon Timestream – Summary
- Managed time-series database
- Use for:
- IoT telemetry
- Application metrics
- Real-time analytics
Features:
- Built-in data lifecycle (store recent data in memory, older data in S3)
- SQL-like queries
✅ Optimized for time-stamped data at scale
Summary Comparison Table
| Service | Type | Best For |
|---|---|---|
| RDS | Relational | Traditional SQL workloads |
| Aurora | Relational | High-performance cloud SQL |
| DynamoDB | NoSQL | Scalable serverless key-value/doc DB |
| ElastiCache | In-memory | Fast cache for queries/sessions |
| S3 | Object Store | Data lakes, unstructured storage |
| DocumentDB | Document | MongoDB-compatible JSON apps |
| Neptune | Graph | Relationship-heavy data |
| Keyspaces | Wide-column | Cassandra-based systems |
| QLDB | Ledger | Immutable logs and audit trails |
| Timestream | Time-series | IoT & metric analytics |