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PostgreSQL vs Microsoft SQL Server

PostgreSQL: The extensible, standards-first open-source relational database. Microsoft SQL Server: Microsoft's flagship RDBMS: T-SQL, columnstore, Always On, and now native vectors and JSON.

key differences

  • Licensing: PostgreSQL is open source (permissive) (PostgreSQL License); Microsoft SQL Server is proprietary (Microsoft commercial license).
  • Microsoft SQL Server is built for larger datasets (≤ 1 PB) than PostgreSQL (≤ 10 TB).
  • Horizontal scaling is addon in PostgreSQL and manual in Microsoft SQL Server.
  • Only PostgreSQL has pub/sub.
  • Only Microsoft SQL Server has columnar storage, in-memory, encryption at rest, 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 sql-server for

  • +Line-of-business apps in .NET shops
  • +ERP and CRM back ends (Dynamics, many ISV products)
  • +Operational reporting with columnstore indexes
  • +Departmental data marts feeding Power BI

best at · OLTP, HTAP, Warehouse

PostgreSQLThe extensible, standards-first open-source relational database.
Microsoft SQL ServerMicrosoft's flagship RDBMS: T-SQL, columnstore, Always On, and now native vectors and JSON.
overview
Primary model
Relational
Relational
Also supports
Document, Spatial
Document, Spatial, Vector, Graph, XML
Type
Database engine
Database engine
Status
Active
Active
Developer
PostgreSQL Global Development Group
Microsoft
First release
1996
1989
Latest version
18.6 (Aug 13, 2026)
2025 CU10 (17.0.5035.5) (Oct 22, 2026)
License
Open source (permissive)PostgreSQL License
ProprietaryMicrosoft commercial license
Free tier
✓
✓
popularity
WhichDB Score
93.2
71.0
Rank
#1
#8
GitHub stars
22.6K
–
Stack Overflow questions
178.8K
336.2K
scale & guarantees
Comfortable data size
Medium (≤ 10 TB)
Large (≤ 1 PB)
Horizontal scaling
Addon
Manual
Multi-region
Read replicas
Read replicas
ACID
Full
Full
Consistency
Strong
Strong
Schema
Strict
Strict
Architecture
Single node, Primary replica, Client server
Client server, Primary replica, Shared storage
deployment
Self-hosted
✓
✓
Vendor-managed cloud
—
✓
Serverless
—
—
Embedded
—
—
Edge
—
—
Clouds
AWS, Google Cloud, Azure, Oracle Cloud, IBM Cloud, Alibaba Cloud
Azure, AWS, Google 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
T-SQL
Client languages
C, Java, Python, JavaScript, Go, Rust, C#, Ruby
C#, Java, Python, JavaScript, Go, PHP, Rust, C
Best for
OLTP, Geo, Search, Content
OLTP, HTAP, Warehouse, Real-time analytics
Add more to this comparisonNot sure either fits? Try smart match

PostgreSQL vs Microsoft SQL Server: FAQ

What is the difference between PostgreSQL and Microsoft SQL Server?

PostgreSQL: The extensible, standards-first open-source relational database. Microsoft SQL Server: Microsoft's flagship RDBMS: T-SQL, columnstore, Always On, and now native vectors and JSON. Licensing: PostgreSQL is open source (permissive) (PostgreSQL License); Microsoft SQL Server is proprietary (Microsoft commercial license). Microsoft SQL Server is built for larger datasets (≤ 1 PB) than PostgreSQL (≤ 10 TB). Horizontal scaling is addon in PostgreSQL and manual in Microsoft SQL Server.

When should I choose PostgreSQL over Microsoft SQL Server?

Choose PostgreSQL for general-purpose application backend, SaaS multi-tenant data and geospatial applications with PostGIS. Choose Microsoft SQL Server for line-of-business apps in .NET shops; ERP and CRM back ends (Dynamics, many ISV products); and operational reporting with columnstore indexes.

Is PostgreSQL or Microsoft SQL Server more popular?

PostgreSQL ranks #1 on the WhichDB Score (93.2/100) and Microsoft SQL Server ranks #8 (71.0/100). Popularity is not fit: check the requirements that matter for your project.

Are PostgreSQL and Microsoft SQL Server open source?

Yes. PostgreSQL is open source. License: PostgreSQL License. No. Microsoft SQL Server is proprietary, closed-source software. License: Microsoft commercial license.