# AWS Postgres
# Amonzon RDS options
- RDS Mysql
- RDS Mssql
- RDS Oracle
- RDS MariaDB
- RDS Postgres
- Aurora (PostgreSQL & MySQL)
# PostgreSQL options
- PostgreSQL on EC2
- Amazon RDS for PostgreSQL
- Amazon Aurora for PostgreSQL
# RDS PostgreSQL vs Aurora PostgreSQL
# Overview
| . | RDS PostgreSQL | Aurora PostgreSQL |
|---|---|---|
| Fully managed | ✅ | ✅ |
| Ideal for | Small-medium intense workload | Commercial workload |
| Various types of instances | ✅ | ✅ |
| Multiple version | ✅ | ✅ |
| PITR | ✅ | ✅ |
| Storage Auto Scaling | ✅ | ✅ |
| Monitoring | ✅ | ✅ |
| Multi-AZ | ✅ | ✅ |
# Archiecture
# Replication
| . | RDS PostgreSQL | Aurora PostgreSQL |
|---|---|---|
| Storage supported | 64TB | 128TB |
| Storage Types | EBS | High performance subsystem customized |
| Read Replicas | 5 | 15 |
| Cross-region read replicas | ✅ | ✅ |
| Replica Lag | Few seconds | Few hundred-milliseconds |
| Max lag | Few minutes | 30 seconds |
| Replica Sync Types | Async | Async (lower latency) |
| Replication mechanism | Secondary Replica | Six copies, 3 AZs |
# Storage
| . | RDS PostgreSQL | Aurora PostgreSQL |
|---|---|---|
| Max size | 64TB | 128TB |
| Auto scaling | 5GB | 10GB |
| OPS | General Purpose: 16K Provisioned: 80K | No limitation |
| High Available | Multi-AZ | Multi-AZ |
| Lag | Few seconds | Milliseconds |
| Number of AZ | 2 | 3 |
| Global DB | ❌ | ✅ |
# Crash recovery
| . | RDS PostgreSQL | Aurora PostgreSQL |
|---|---|---|
| Checkpoint recovery | Database node | Storage node |
| Checkpoint Duration | 5 minutes | Quick |
| Failover Automation | ✅ | ✅ |
| Failover duration | 60-120 seconds | 30 seconds |
# Backup & instance type
| . | RDS PostgreSQL | Aurora PostgreSQL |
|---|---|---|
| Automation Backup | ✅ | ✅ |
| Performance Impact | Slightly | ❌ |
| Restore | Full backup + WALs (Transaction logs) | Incremental (Quick restore) |
| RPO, RTO | Fast | Very Fast |
| Instance classes | T2, T3, M3, M4, M5 R3, R4, R5 | T3, R4, R5 |
| AWS Graviton2 Support | ✅ | ✅ |
| Database Cloning | ❌ | ✅ |
| Query Plan Management | ❌ | ✅ |
| Serverless | ❌ | ✅ |
# Refs
https://aws.amazon.com/blogs/database/is-amazon-rds-for-postgresql-or-amazon-aurora-postgresql-a-better-choice-for-me/