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Apache Cassandra vs PostgreSQL

Side-by-side comparison of Apache Cassandra and PostgreSQL. Data-driven analysis for CTOs and engineering leaders.

Technical Profile

Apache Cassandra

Scalability
very high
Performance
very high
Learning Curve
steep
Maturity
mature
Languages: Java

PostgreSQL

Scalability
high
Performance
high
Learning Curve
moderate
Maturity
mature
Languages: C, SQL, PL/pgSQL

When to Use

Apache Cassandra

  • +Need massive write throughput
  • +Multi-datacenter deployment
  • +Time-series data
  • +Always-on availability

Avoid Apache Cassandra when

  • -Complex queries needed
  • -Small team
  • -Limited ops expertise

PostgreSQL

  • +Need ACID guarantees
  • +Complex queries and joins
  • +Data integrity is critical
  • +Flexible schema evolution
  • +Multi-model data (relational + JSON)

Avoid PostgreSQL when

  • -Simple key-value storage only
  • -Need massive horizontal scale out of box
  • -Team only knows NoSQL

Compliance & Security

Apache Cassandra

SOC 2GDPRHIPAAPCI-DSS

Security Features

EncryptionAudit LogsRBACMFA

PostgreSQL

SOC 2GDPRHIPAAPCI-DSS

Security Features

EncryptionAudit LogsRBACMFA

Operations

Apache Cassandra

Maintenance
high
Monitoring
high
Backup/Recovery
moderate
Hosting: self-hosted, cloud, managed

PostgreSQL

Maintenance
medium
Monitoring
medium
Backup/Recovery
moderate
Hosting: self-hosted, cloud, managed

Frequently Asked Questions

How does scalability compare between Apache Cassandra and PostgreSQL?

Apache Cassandra offers very-high scalability, while PostgreSQL offers high scalability. Consider your expected traffic and data volume when choosing.

Which has the easier learning curve: Apache Cassandra or PostgreSQL?

Apache Cassandra has a steep learning curve, while PostgreSQL has a moderate learning curve. Factor in your team's existing skills and onboarding timeline.

What are the pricing differences between Apache Cassandra and PostgreSQL?

Apache Cassandra uses a free pricing model with a free tier. PostgreSQL uses a free pricing model with a free tier. Evaluate total cost of ownership including operational overhead.

Which option is better for compliance: Apache Cassandra or PostgreSQL?

Apache Cassandra supports SOC 2, GDPR, HIPAA, PCI-DSS. PostgreSQL supports SOC 2, GDPR, HIPAA, PCI-DSS. Always verify current certifications directly with the vendor.

Need help deciding between Apache Cassandra vs PostgreSQL?

Use our interactive decision tool for a personalized recommendation.

Apache Cassandra vs PostgreSQL — CTO Technology Comparison | The Art of CTO