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IBM Informix vs PostgreSQL

IBM Informix: Low-maintenance embeddable RDBMS with built-in TimeSeries, still quietly running retail and telco systems. PostgreSQL: The extensible, standards-first open-source relational database.

key differences

  • Licensing: IBM Informix is proprietary (Proprietary commercial license); PostgreSQL is open source (permissive) (PostgreSQL License).
  • Only IBM Informix has encryption at rest.
  • Only PostgreSQL has vector search, materialized views, pub/sub.

choose ibm-informix for

  • +Retail store and point-of-sale back ends
  • +Smart-meter and utility time-series data
  • +Telecom provisioning systems
  • +Embedded databases inside OEM appliances

best at · OLTP, Time-series, IoT

choose postgresql for

  • +General-purpose application backend
  • +SaaS multi-tenant data
  • +Geospatial applications with PostGIS
  • +Semantic search alongside relational data with pgvector

best at · OLTP, Geo, Search

IBM InformixLow-maintenance embeddable RDBMS with built-in TimeSeries, still quietly running retail and telco systems.
PostgreSQLThe extensible, standards-first open-source relational database.
overview
Primary model
Relational
Relational
Also supports
Time-Series, Document, Spatial
Document, Spatial
Type
Database engine
Database engine
Status
Active
Active
Developer
IBM (co-developed with HCLSoftware)
PostgreSQL Global Development Group
First release
1981
1996
Latest version
15.0.1.18 (Sep 30, 2026)
18.6 (Aug 13, 2026)
License
ProprietaryProprietary commercial license
Open source (permissive)PostgreSQL License
Free tier
✓
✓
popularity
WhichDB Score
26.0
93.2
Rank
#115
#1
GitHub stars
–
22.6K
Stack Overflow questions
2.3K
178.8K
scale & guarantees
Comfortable data size
Medium (≤ 10 TB)
Medium (≤ 10 TB)
Horizontal scaling
Addon
Addon
Multi-region
Active active
Read replicas
ACID
Full
Full
Consistency
Strong
Strong
Schema
Strict
Strict
Architecture
Client server, Primary replica, Multi primary, Shared storage
Single node, Primary replica, Client server
deployment
Self-hosted
✓
✓
Vendor-managed cloud
—
—
Serverless
—
—
Embedded
—
—
Edge
—
—
Clouds
–
AWS, Google Cloud, Azure, Oracle Cloud, IBM Cloud, Alibaba Cloud
capabilities
Transactions
✓
✓
Joins
✓
✓
Secondary indexes
✓
✓
Full-text search
✓
✓
Vector search
—
✓
Geospatial
✓
✓
JSON
✓
✓
Change data capture
✓
✓
Triggers
✓
✓
Stored procedures
✓
✓
Materialized views
—
✓
TTL / expiry
—
—
Pub/Sub
—
✓
Columnar storage
—
—
In-memory
—
—
Durable persistence
✓
✓
Compression
✓
✓
Encryption at rest
✓
—
Role-based access
✓
✓
Time travel
—
—
Branching
—
—
Online schema changes
✓
✓
Streaming ingest
—
—
Offline sync
—
—
Runs in WebAssembly
—
—
interfaces
Query languages
SQL, SPL
SQL, PL/pgSQL
Client languages
C, Java, Python, JavaScript, C#, ESQL/C
C, Java, Python, JavaScript, Go, Rust, C#, Ruby
Best for
OLTP, Time-series, IoT, Embedded
OLTP, Geo, Search, Content
Add more to this comparisonNot sure either fits? Try smart match

IBM Informix vs PostgreSQL: FAQ

What is the difference between IBM Informix and PostgreSQL?

IBM Informix: Low-maintenance embeddable RDBMS with built-in TimeSeries, still quietly running retail and telco systems. PostgreSQL: The extensible, standards-first open-source relational database. Licensing: IBM Informix is proprietary (Proprietary commercial license); PostgreSQL is open source (permissive) (PostgreSQL License). Only IBM Informix has encryption at rest. Only PostgreSQL has vector search, materialized views, pub/sub.

When should I choose IBM Informix over PostgreSQL?

Choose IBM Informix for retail store and point-of-sale back ends; smart-meter and utility time-series data; and telecom provisioning systems. Choose PostgreSQL for general-purpose application backend, SaaS multi-tenant data and geospatial applications with PostGIS.

Is IBM Informix or PostgreSQL more popular?

PostgreSQL ranks #1 on the WhichDB Score (93.2/100) and IBM Informix ranks #115 (26.0/100). Popularity is not fit: check the requirements that matter for your project.

Are IBM Informix and PostgreSQL open source?

No. IBM Informix is proprietary, closed-source software. Yes. PostgreSQL is open source. License: PostgreSQL License.