whichdb
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PostgreSQL vs Oracle Rdb

PostgreSQL: The extensible, standards-first open-source relational database. Oracle Rdb: DEC's relational database for OpenVMS, owned by Oracle since 1994 and still updated on Alpha and Itanium.

key differences

  • Licensing: PostgreSQL is open source (permissive) (PostgreSQL License); Oracle Rdb is proprietary (Oracle proprietary license).
  • Horizontal scaling is addon in PostgreSQL and none in Oracle Rdb.
  • Only PostgreSQL has full-text search, vector search, geospatial, json, change data capture.

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

choose rdb-vms for

  • +Running existing OpenVMS line-of-business systems
  • +Banking, manufacturing and government applications on OpenVMS clusters
  • +Modernising RMS-file applications without leaving OpenVMS

best at · OLTP

PostgreSQLThe extensible, standards-first open-source relational database.
Oracle RdbDEC's relational database for OpenVMS, owned by Oracle since 1994 and still updated on Alpha and Itanium.
overview
Primary model
Relational
Relational
Also supports
Document, Spatial
–
Type
Database engine
Database engine
Status
Active
Active
Developer
PostgreSQL Global Development Group
Oracle Corporation (originally Digital Equipment Corporation)
First release
1996
1984
Latest version
18.6 (Aug 13, 2026)
7.4.1.5 (Jan 2026)
License
Open source (permissive)PostgreSQL License
ProprietaryOracle proprietary license
Free tier
✓
—
popularity
WhichDB Score
93.2
4.8
Rank
#1
#396
GitHub stars
22.6K
–
Stack Overflow questions
178.8K
–
scale & guarantees
Comfortable data size
Medium (≤ 10 TB)
Medium (≤ 10 TB)
Horizontal scaling
Addon
None
Multi-region
Read replicas
None
ACID
Full
Full
Consistency
Strong
Strong
Schema
Strict
Strict
Architecture
Single node, Primary replica, Client server
Single node, Shared storage, 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, PL/pgSQL
SQL, RDO (Relational Database Operator)
Client languages
C, Java, Python, JavaScript, Go, Rust, C#, Ruby
COBOL, C, BASIC, Fortran, Pascal
Best for
OLTP, Geo, Search, Content
OLTP
Add more to this comparisonNot sure either fits? Try smart match

PostgreSQL vs Oracle Rdb: FAQ

What is the difference between PostgreSQL and Oracle Rdb?

PostgreSQL: The extensible, standards-first open-source relational database. Oracle Rdb: DEC's relational database for OpenVMS, owned by Oracle since 1994 and still updated on Alpha and Itanium. Licensing: PostgreSQL is open source (permissive) (PostgreSQL License); Oracle Rdb is proprietary (Oracle proprietary license). Horizontal scaling is addon in PostgreSQL and none in Oracle Rdb. Only PostgreSQL has full-text search, vector search, geospatial, json, change data capture.

When should I choose PostgreSQL over Oracle Rdb?

Choose PostgreSQL for general-purpose application backend, SaaS multi-tenant data and geospatial applications with PostGIS. Choose Oracle Rdb for running existing OpenVMS line-of-business systems; banking, manufacturing and government applications on OpenVMS clusters; and modernising RMS-file applications without leaving OpenVMS.

Is PostgreSQL or Oracle Rdb more popular?

PostgreSQL ranks #1 on the WhichDB Score (93.2/100) and Oracle Rdb ranks #396 (4.8/100). Popularity is not fit: check the requirements that matter for your project.

Are PostgreSQL and Oracle Rdb open source?

Yes. PostgreSQL is open source. License: PostgreSQL License. No. Oracle Rdb is proprietary, closed-source software.