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PostgreSQL vs XTDB

PostgreSQL: The extensible, standards-first open-source relational database. XTDB: Bitemporal SQL database on object storage that keeps every version of every row.

key differences

  • Licensing: PostgreSQL is open source (permissive) (PostgreSQL License); XTDB is open source (copyleft) (Mozilla Public License 2.0).
  • Horizontal scaling is addon in PostgreSQL and manual in XTDB.
  • Only PostgreSQL has secondary indexes, full-text search, vector search, geospatial, change data capture.
  • Only XTDB has columnar storage, time travel.

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 xtdb for

  • +Financial and insurance systems needing as-of reporting
  • +Audit trails with retroactive corrections
  • +Event-sourced systems wanting SQL over history

best at · OLTP, Event sourcing, Ledger

PostgreSQLThe extensible, standards-first open-source relational database.
XTDBBitemporal SQL database on object storage that keeps every version of every row.
overview
Primary model
Relational
Relational
Also supports
Document, Spatial
Document, Columnar / OLAP
Type
Database engine
Database engine
Status
Active
Active
Developer
PostgreSQL Global Development Group
JUXT Ltd
First release
1996
2019
Latest version
18.6 (Aug 13, 2026)
2.2.0 (Oct 21, 2026)
License
Open source (permissive)PostgreSQL License
Open source (copyleft)Mozilla Public License 2.0
Free tier
✓
✓
popularity
WhichDB Score
93.2
8.3
Rank
#1
#328
GitHub stars
22.6K
3.1K
Stack Overflow questions
178.8K
7
scale & guarantees
Comfortable data size
Medium (≤ 10 TB)
Medium (≤ 10 TB)
Horizontal scaling
Addon
Manual
Multi-region
Read replicas
None
ACID
Full
Full
Consistency
Strong
Strong
Schema
Strict
Flexible
Architecture
Single node, Primary replica, Client server
Distributed, Shared storage
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, XTQL
Client languages
C, Java, Python, JavaScript, Go, Rust, C#, Ruby
Java, Kotlin, Clojure, Python, JavaScript, Go
Best for
OLTP, Geo, Search, Content
OLTP, Event sourcing, Ledger, HTAP
Add more to this comparisonNot sure either fits? Try smart match

PostgreSQL vs XTDB: FAQ

What is the difference between PostgreSQL and XTDB?

PostgreSQL: The extensible, standards-first open-source relational database. XTDB: Bitemporal SQL database on object storage that keeps every version of every row. Licensing: PostgreSQL is open source (permissive) (PostgreSQL License); XTDB is open source (copyleft) (Mozilla Public License 2.0). Horizontal scaling is addon in PostgreSQL and manual in XTDB. Only PostgreSQL has secondary indexes, full-text search, vector search, geospatial, change data capture.

When should I choose PostgreSQL over XTDB?

Choose PostgreSQL for general-purpose application backend, SaaS multi-tenant data and geospatial applications with PostGIS. Choose XTDB for financial and insurance systems needing as-of reporting; audit trails with retroactive corrections; and event-sourced systems wanting SQL over history.

Is PostgreSQL or XTDB more popular?

PostgreSQL ranks #1 on the WhichDB Score (93.2/100) and XTDB ranks #328 (8.3/100). Popularity is not fit: check the requirements that matter for your project.

Are PostgreSQL and XTDB open source?

Yes. PostgreSQL is open source. License: PostgreSQL License. Yes. XTDB is open source. License: Mozilla Public License 2.0.