Azure Database for PostgreSQL and MySQL

Azure provides fully managed database services for the two most popular open-source relational database engines: PostgreSQL and MySQL. These services handle infrastructure management, patching, backups, and high availability while remaining compatible with the community editions of each engine.

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Azure Database for PostgreSQL

Deployment Options

Option	Status	Description
Flexible Server	Recommended	Full control over configuration, zone-redundant HA, and stop/start capability
Single Server	Retirement announced	Simpler model with fewer options; migrate to Flexible Server
Cosmos DB for PostgreSQL	Available	Distributed PostgreSQL (Citus) for multi-node, horizontally scaled workloads

Flexible Server is the recommended deployment for all new PostgreSQL workloads on Azure.

Flexible Server Architecture

Availability Zone 1              Availability Zone 2
┌──────────────────┐             ┌──────────────────┐
│  Primary Server  │  ────────>  │  Standby Server  │
│  (Compute + Data)│  synchronous│  (Compute + Data)│
└──────────────────┘  replication└──────────────────┘

Feature	Detail
PostgreSQL versions	13, 14, 15, 16
Compute tiers	Burstable (B-series), General Purpose (D-series), Memory Optimised (E-series)
Max storage	16 TB
Max connections	Depends on compute tier (e.g., 5,000 for 64 vCores)
HA SLA	99.99% with zone-redundant HA
Backups	Automatic, up to 35 days retention

High Availability

Flexible Server offers two HA modes:

Mode	Description	Failover Time
Zone-redundant	Standby in a different availability zone	~60–120 seconds
Same-zone	Standby in the same zone	~60–120 seconds

During failover, the standby is promoted to primary. DNS is updated to point to the new primary. Connections must be re-established (use retry logic in your application).

Key Features

• Extensions — PostGIS, pg_stat_statements, pgvector (for AI/ML vector search), pg_cron, pgaudit, and 50+ others
• Connection pooling — built-in PgBouncer for managing connection overhead
• Read replicas — up to 10 read replicas (including cross-region) for offloading read traffic
• Stop/Start — stop the server when not in use (development/testing) to save compute costs
• Intelligent performance — Query Performance Insight and automatic index recommendations
• Microsoft Entra ID authentication — authenticate using Azure identities

Networking

Option	Description
Public access	Accessible over the internet with firewall rules
Private access (VNet integration)	Deployed into a delegated subnet in your VNet
Private endpoint	Access over a private IP via Azure Private Link

For production, use VNet integration or private endpoints to keep database traffic off the public internet.

Creating a Flexible Server

az postgres flexible-server create \
  --resource-group rg-demo \
  --name my-pg-server \
  --location uksouth \
  --tier GeneralPurpose \
  --sku-name Standard_D4ds_v5 \
  --storage-size 128 \
  --version 16 \
  --high-availability ZoneRedundant \
  --admin-user pgadmin \
  --admin-password '<strong-password>'

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Azure Database for MySQL

Deployment Options

Option	Status	Description
Flexible Server	Recommended	Configurable compute, storage, HA, and stop/start
Single Server	Retirement announced	Simpler model; migrate to Flexible Server

Flexible Server Architecture

Similar to PostgreSQL Flexible Server:

Feature	Detail
MySQL versions	5.7, 8.0
Compute tiers	Burstable, General Purpose, Business Critical
Max storage	16 TB
HA SLA	99.99% with zone-redundant HA
Backups	Automatic, up to 35 days retention

High Availability

MySQL Flexible Server uses MySQL Group Replication for HA: