Cloud-native, serverless & distributed SQL
Amazon Aurora PostgreSQL-Compatible Edition vs Azure HorizonDB / Azure Database for PostgreSQL (flexible server)
Microsoft maps Amazon Aurora PostgreSQL to Azure HorizonDB, a PostgreSQL service with disaggregated compute and storage.
HorizonDB was in public preview when verified, so for production today the usual Azure target is Azure Database for PostgreSQL (flexible server).
Side-by-side comparison
| Aspect | Amazon Web Services | Microsoft Azure |
|---|---|---|
| Service | Amazon Aurora PostgreSQL-Compatible Edition | Azure HorizonDB Preview Azure Database for PostgreSQL (flexible server) |
| Lifecycle | Generally available | Public preview when verified. Microsoft says to confirm its status before planning a production migration. Generally available |
| What it is | PostgreSQL-compatible engine with a distributed storage volume that keeps copies across three AZs, up to 15 low-lag read replicas, fast cloning, Global Database, Serverless v2, I/O-Optimized pricing, and Limitless Database. | Cloud-native PostgreSQL service with disaggregated compute and storage and a database-as-a-log design. Storage is zone-resilient by default and grows automatically, and read replicas share the storage. Managed community PostgreSQL in Burstable, General Purpose, and Memory Optimized tiers, with same-zone or zone-redundant HA (synchronous warm standby), read replicas, built-in PgBouncer, in-place major version upgrades, stop/start, and extensions such as pgvector. |
| Pricing model | Per instance-hour (or ACU-hour for Serverless v2), plus storage per GB-month, and I/O requests on Aurora Standard (I/O-Optimized has no I/O charge but higher instance and storage prices). | HorizonDB is billed for compute and storage per its preview pricing page. Flexible server is billed per vCore-hour plus storage. |
| Docs | Amazon Aurora PostgreSQL-Compatible Edition docs | Azure HorizonDB docs Azure Database for PostgreSQL (flexible server) docs |
| Pricing page | Amazon Aurora PostgreSQL-Compatible Edition pricing | Azure HorizonDB pricing Azure Database for PostgreSQL (flexible server) pricing |
| Exams | SAA-C03 SAP-C02 Retiring DVA-C02 Retiring | AZ-305 |
Key differences
- Maturity. Aurora PostgreSQL has been generally available for years and includes Global Database, Serverless v2, Limitless Database, Babelfish, and zero-ETL. HorizonDB is in preview, and Microsoft advises confirming its status before planning a production migration.
- Architecture. Both separate stateless compute from a distributed, zone-resilient storage layer and add read replicas that share storage. HorizonDB uses a database-as-a-log design with separate WAL and data storage fleets.
- Flexible server is a classic single-node-plus-standby design. It's mature, but it isn't a shared-storage cluster.
Pricing summary
Pricing models only. No prices are quoted because they change by region and over time.
- AWS
- Per instance-hour (or ACU-hour for Serverless v2), plus storage per GB-month, and I/O requests on Aurora Standard (I/O-Optimized has no I/O charge but higher instance and storage prices). Amazon Aurora PostgreSQL-Compatible Edition pricing →
- Azure
- HorizonDB is billed for compute and storage per its preview pricing page. Flexible server is billed per vCore-hour plus storage. Azure HorizonDB pricing → Azure Database for PostgreSQL (flexible server) pricing →
Certification exam mapping
| Exam | Provider | Level | Status |
|---|---|---|---|
| AWS Certified Solutions Architect – Associate SAA-C03 | AWS | Associate | current Italian version retires after Dec 31, 2026. |
| AWS Certified Solutions Architect – Professional SAP-C02 | AWS | Professional | retiring Being updated to SAP-C03. Registration for SAP-C03 opens Oct 27, 2026. Last day to take SAP-C02 is Nov 16, 2026. |
| AWS Certified Developer – Associate DVA-C02 | AWS | Associate | retiring Being updated to DVA-C03. Registration for DVA-C03 opens Oct 27, 2026. Last day to take DVA-C02 is Nov 30, 2026. |
| Microsoft Certified – Azure Solutions Architect Expert AZ-305 | Azure | Expert | current English version updated Apr 17, 2026. |
Relevance is based on each exam's published scope, not a line-by-line objective match. Check the official study guide.
Verification notes
- HorizonDB was in preview when verified. Check for GA, region availability, and pricing before planning on it.
FAQ
What is the Azure equivalent of Amazon Aurora PostgreSQL-Compatible Edition?
Microsoft maps Amazon Aurora PostgreSQL to Azure HorizonDB, a PostgreSQL service with disaggregated compute and storage. HorizonDB was in public preview when verified, so for production today the usual Azure target is Azure Database for PostgreSQL (flexible server).
How does pricing compare between Amazon Aurora PostgreSQL-Compatible Edition and Azure HorizonDB and Azure Database for PostgreSQL (flexible server)?
AWS: Per instance-hour (or ACU-hour for Serverless v2), plus storage per GB-month, and I/O requests on Aurora Standard (I/O-Optimized has no I/O charge but higher instance and storage prices). Azure: HorizonDB is billed for compute and storage per its preview pricing page. Flexible server is billed per vCore-hour plus storage. Check the official pricing pages for current rates.
Which certification exams cover this topic?
AWS Certified Solutions Architect – Associate (SAA-C03); AWS Certified Solutions Architect – Professional (SAP-C02) [retiring]; AWS Certified Developer – Associate (DVA-C02) [retiring]; Microsoft Certified – Azure Solutions Architect Expert (AZ-305).