PostgreSQL vs Amazon Aurora: Cloud Database Showdown

Comprehensive comparison between standard PostgreSQL and Amazon's cloud-native Aurora. Discover which database delivers better performance, cost-effectiveness, and scalability for your cloud workloads.

PostgreSQL

Open Source

VS

Amazon Aurora

Cloud-Native

PostgreSQL vs Aurora: Key Differences

Feature PostgreSQL Amazon Aurora
Deployment Any platform AWS only
Performance Excellent Up to 3x faster
Scalability Manual scaling Auto-scaling
High Availability Requires setup Built-in
Backup & Recovery Manual setup Automated
Cost (Small) Lower Higher
Cost (Large) Variable Competitive

Architecture & Design Philosophy

PostgreSQL: Traditional Architecture

Core Characteristics

  • Single-node primary architecture
  • Shared-nothing design
  • Local storage with WAL
  • Manual replication setup
  • Platform-agnostic deployment
  • Full control over configuration

Scaling Approach

  • Vertical scaling (scale up)
  • Read replicas for read scaling
  • Manual failover processes
  • Third-party clustering solutions

Aurora: Cloud-Native Architecture

Core Characteristics

  • Distributed storage layer
  • Compute and storage separation
  • 6-way replicated storage
  • Automatic failover (< 30 seconds)
  • AWS-native integration
  • Managed service benefits

Scaling Approach

  • Auto-scaling compute and storage
  • Up to 15 read replicas
  • Aurora Serverless for variable workloads
  • Global database for multi-region

Performance Benchmarks

OLTP Performance (Sysbench)

PostgreSQL
14,000 TPS
Aurora PostgreSQL
20,000 TPS

Aurora shows significant performance improvements for OLTP workloads.

Read Replica Performance

PostgreSQL
45,000 QPS
Aurora PostgreSQL
60,000 QPS

Aurora's shared storage enables faster read replica performance.

Failover Time

PostgreSQL
60-120 seconds
Aurora PostgreSQL
< 30 seconds

Aurora provides much faster automatic failover capabilities.

Cost Analysis

Small Application (2 vCPU, 8GB RAM)

PostgreSQL on EC2

EC2 Instance (t3.large) $67/month
EBS Storage (100GB) $10/month
Backup Storage $5/month
Total Monthly Cost $82

Aurora PostgreSQL

Aurora Instance (db.t3.medium) $58/month
Storage (100GB) $10/month
I/O Operations $15/month
Total Monthly Cost $83

Large Application (16 vCPU, 64GB RAM)

PostgreSQL on EC2

EC2 Instance (r5.4xlarge) $1,008/month
EBS Storage (1TB) $100/month
Read Replicas (2x) $2,016/month
Total Monthly Cost $3,124

Aurora PostgreSQL

Aurora Instance (db.r5.4xlarge) $1,440/month
Storage (1TB) $100/month
Read Replicas (2x) $2,880/month
Total Monthly Cost $4,420

Feature Comparison

High Availability & Disaster Recovery

PostgreSQL

  • Manual streaming replication setup
  • Point-in-time recovery with WAL
  • Third-party HA solutions (Patroni)
  • Manual failover processes
  • Cross-region replication setup
  • Backup scheduling required

Amazon Aurora

  • Automatic failover (< 30 seconds)
  • Continuous backup to S3
  • 6-way storage replication
  • Up to 15 read replicas
  • Global database for DR
  • Automated backup retention

Scaling & Performance

PostgreSQL

  • Vertical scaling with downtime
  • Manual read replica management
  • Connection pooling setup required
  • Manual storage expansion
  • Performance tuning needed
  • Custom monitoring setup

Amazon Aurora

  • Auto-scaling compute and storage
  • Aurora Serverless for variable loads
  • Built-in connection pooling
  • Storage auto-scales to 128TB
  • Performance Insights included
  • CloudWatch integration

Management & Operations

PostgreSQL

  • Full administrative control
  • Custom configuration options
  • Manual patching and updates
  • Self-managed security
  • Custom extension installation
  • DIY monitoring and alerting

Amazon Aurora

  • Managed service (limited control)
  • AWS-optimized configuration
  • Automatic patching
  • AWS security integration
  • Limited extension support
  • Built-in monitoring and alerting

Serverless & Auto-Scaling Capabilities

PostgreSQL Serverless Options

Third-Party Solutions

  • Neon - Serverless PostgreSQL
  • PlanetScale - Serverless database platform
  • Supabase - Backend-as-a-Service
  • Railway - Application hosting with PostgreSQL

Characteristics

  • Pay-per-use pricing models
  • Automatic scaling capabilities
  • Cold start considerations
  • Limited to specific providers

Aurora Serverless

Aurora Serverless v2

  • Instant scaling (0.5 to 128 ACUs)
  • Per-second billing
  • No cold starts
  • Compatible with Aurora features

Use Cases

  • Variable workloads
  • Development environments
  • Infrequent applications
  • Cost optimization scenarios

Migration Considerations

PostgreSQL to Aurora

Benefits

  • Improved performance and scalability
  • Reduced operational overhead
  • Built-in high availability
  • AWS ecosystem integration

Migration Process

  • AWS Database Migration Service (DMS)
  • pg_dump/pg_restore for smaller databases
  • Logical replication for minimal downtime
  • Blue-green deployment strategies

Considerations

  • AWS vendor lock-in
  • Potential cost increases
  • Limited extension support
  • Configuration restrictions

Aurora to PostgreSQL

Reasons to Migrate

  • Cost optimization
  • Multi-cloud strategy
  • Full control requirements
  • Custom extension needs

Migration Challenges

  • Loss of managed service benefits
  • Increased operational complexity
  • HA/DR setup requirements
  • Performance optimization needs

Migration Tools

  • pg_dump/pg_restore
  • Logical replication
  • Third-party migration tools
  • Custom ETL processes

When to Choose PostgreSQL vs Aurora

Choose PostgreSQL When:

  • Multi-cloud or on-premises deployment
  • Cost optimization is critical
  • Full control over configuration needed
  • Custom extensions required
  • Avoiding vendor lock-in
  • Small to medium workloads
  • Existing PostgreSQL expertise
  • Compliance requires specific configurations

Choose Aurora When:

  • AWS-native applications
  • High availability requirements
  • Variable or unpredictable workloads
  • Minimal operational overhead desired
  • Global application deployment
  • Large-scale applications
  • Rapid scaling requirements
  • AWS ecosystem integration benefits

PostgreSQL vs Aurora: Frequently Asked Questions

Is Aurora really 3x faster than PostgreSQL?

Aurora can be up to 3x faster than PostgreSQL in specific scenarios, particularly for I/O-intensive workloads. This performance improvement comes from Aurora's distributed storage architecture and optimizations. However, actual performance depends on your specific workload and configuration.

Can I migrate from PostgreSQL to Aurora without downtime?

Yes, you can achieve near-zero downtime migration using AWS Database Migration Service (DMS) with ongoing replication, or by setting up logical replication between PostgreSQL and Aurora. The exact approach depends on your database size and acceptable downtime window.

What PostgreSQL extensions are not supported in Aurora?

Aurora supports most popular PostgreSQL extensions but has limitations on extensions that require superuser privileges or modify core PostgreSQL behavior. Check AWS documentation for the current list of supported extensions before migration.

Is Aurora more expensive than self-managed PostgreSQL?

Aurora typically costs more than self-managed PostgreSQL on EC2, especially for smaller workloads. However, when factoring in operational overhead, high availability setup, and management costs, Aurora can be cost-competitive for larger applications.

Can I use Aurora outside of AWS?

No, Aurora is an AWS-exclusive service and cannot be deployed outside of AWS infrastructure. If you need multi-cloud deployment, standard PostgreSQL is the better choice.

How does Aurora Serverless compare to traditional Aurora?

Aurora Serverless automatically scales compute capacity based on demand and bills per second, making it ideal for variable workloads. Traditional Aurora provides consistent performance with manual scaling but requires you to provision and pay for fixed capacity.