Getting Started with Azure Cosmos DB for PostgreSQL

Azure Cosmos DB for PostgreSQL (formerly known as Hyperscale Citus) brings the power of distributed computing to your PostgreSQL workloads. This managed service allows you to scale out your PostgreSQL database horizontally across multiple nodes.

What is Azure Cosmos DB for PostgreSQL?

Azure Cosmos DB for PostgreSQL is a managed database service that extends PostgreSQL with distributed capabilities. It uses the Citus extension to transform PostgreSQL into a distributed database capable of handling massive workloads.

Key Features

• Horizontal scaling: Distribute data across multiple nodes
• High performance: Parallel query execution across shards
• PostgreSQL compatibility: Use your existing PostgreSQL skills and tools
• Managed service: Azure handles maintenance, backups, and updates

Creating Your First Cluster

# Using Azure CLI to create a Cosmos DB for PostgreSQL cluster
az cosmosdb postgres cluster create \
    --name mypostgrescluster \
    --resource-group myResourceGroup \
    --location eastus \
    --coordinator-vcores 4 \
    --coordinator-storage-size 512 \
    --node-count 2 \
    --node-vcores 4 \
    --node-storage-size 512

Connecting to Your Cluster

Once your cluster is provisioned, you can connect using any PostgreSQL client:

import psycopg2

connection = psycopg2.connect(
    host="c-mypostgrescluster.postgres.cosmos.azure.com",
    database="citus",
    user="citus",
    password="your_password",
    port=5432,
    sslmode="require"
)

cursor = connection.cursor()
cursor.execute("SELECT version();")
print(cursor.fetchone())

When to Use Cosmos DB for PostgreSQL

Consider this service when:

• Your single-node PostgreSQL is reaching its limits
• You need to handle millions of requests per second
• Your dataset is growing beyond what a single server can handle
• You want the familiarity of PostgreSQL with distributed capabilities

In upcoming posts, we’ll dive deeper into sharding strategies, distributed queries, and performance optimization techniques.