whichdb
vs

Azure Database for PostgreSQL vs Azure SQL Database

Azure Database for PostgreSQL: Microsoft's managed community PostgreSQL, with zone-redundant HA, DiskANN vectors and Citus elastic clusters. Azure SQL Database: Microsoft's always-current managed SQL Server engine, from free serverless databases to 128 TB Hyperscale.

key differences

  • Azure SQL Database is built for larger datasets (≤ 1 PB) than Azure Database for PostgreSQL (≤ 10 TB).
  • Horizontal scaling is addon in Azure Database for PostgreSQL and manual in Azure SQL Database.
  • Only Azure Database for PostgreSQL has pub/sub.
  • Only Azure SQL Database has columnar storage, in-memory, compression, time travel, online schema changes.
  • Azure SQL Database has a serverless option; Azure Database for PostgreSQL does not.

choose azure-database-for-postgresql for

  • +Postgres backends for Azure-hosted apps
  • +AI copilots with vectors and relational data together
  • +Migrating Oracle or on-prem Postgres into Azure
  • +Multi-tenant SaaS using Elastic Clusters

best at · OLTP, Vector search, RAG

choose azure-sql-database for

  • +Lift-and-modernize of SQL Server applications
  • +.NET SaaS backends with elastic pools per tenant
  • +Large OLTP databases on Hyperscale
  • +Intermittent dev/test workloads on serverless auto-pause

best at · OLTP, HTAP, Content

Azure Database for PostgreSQLMicrosoft's managed community PostgreSQL, with zone-redundant HA, DiskANN vectors and Citus elastic clusters.
Azure SQL DatabaseMicrosoft's always-current managed SQL Server engine, from free serverless databases to 128 TB Hyperscale.
overview
Primary model
Relational
Relational
Also supports
Document, Spatial, Vector, Graph
Document, Spatial, Graph, Vector, Ledger
Type
Managed service
Managed service
Status
Active
Active
Developer
Microsoft
Microsoft
First release
2017
2010
Latest version
–
–
License
ProprietaryProprietary (Azure service; engine is PostgreSQL License)
ProprietaryProprietary (Azure service)
Free tier
✓
✓
popularity
WhichDB Score
4.9
33.9
Rank
#392
#61
GitHub stars
–
–
Stack Overflow questions
214
10.1K
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
Primary replica, Client server, Distributed
Primary replica, Shared storage, Serverless
deployment
Self-hosted
—
—
Vendor-managed cloud
✓
✓
Serverless
—
✓
Embedded
—
—
Edge
—
—
Clouds
Azure
Azure
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, PHP, Ruby, Rust
C#, Java, Python, JavaScript, Go, PHP, Ruby, C++
Best for
OLTP, Vector search, RAG, Geo
OLTP, HTAP, Content, Ledger
Add more to this comparisonNot sure either fits? Try smart match

Azure Database for PostgreSQL vs Azure SQL Database: FAQ

What is the difference between Azure Database for PostgreSQL and Azure SQL Database?

Azure Database for PostgreSQL: Microsoft's managed community PostgreSQL, with zone-redundant HA, DiskANN vectors and Citus elastic clusters. Azure SQL Database: Microsoft's always-current managed SQL Server engine, from free serverless databases to 128 TB Hyperscale. Azure SQL Database is built for larger datasets (≤ 1 PB) than Azure Database for PostgreSQL (≤ 10 TB). Horizontal scaling is addon in Azure Database for PostgreSQL and manual in Azure SQL Database. Only Azure Database for PostgreSQL has pub/sub.

When should I choose Azure Database for PostgreSQL over Azure SQL Database?

Choose Azure Database for PostgreSQL for postgres backends for Azure-hosted apps; AI copilots with vectors and relational data together; and migrating Oracle or on-prem Postgres into Azure. Choose Azure SQL Database for lift-and-modernize of SQL Server applications, .NET SaaS backends with elastic pools per tenant and large OLTP databases on Hyperscale.

Is Azure Database for PostgreSQL or Azure SQL Database more popular?

Azure SQL Database ranks #61 on the WhichDB Score (33.9/100) and Azure Database for PostgreSQL ranks #392 (4.9/100). Popularity is not fit: check the requirements that matter for your project.

Are Azure Database for PostgreSQL and Azure SQL Database open source?

No. Azure Database for PostgreSQL is proprietary, closed-source software. No. Azure SQL Database is proprietary, closed-source software.