How much? Be careful when provisioning Scalable Azure SQL Databases

TL;DR Ensure you pick Serverless when using the Azure SQL Database General Purpose (Scalable compute and storage options) or you could spend a lot more than you intended.

Funny story one of our Azure Subscriptions hit its spending limit unexpectedly. We have spending limits on all our Azure Subscriptions as it’s just too easy to create a costly Azure Resource. Fortunately this was in a subscription we use for testing which has a low spending limit.

Most months it uses less than £10, this month it hit £100 in a coupel of weeks. What had changed?

We are creating a Remix Stack for Azure and as part of that we use Prisma to manage the database. I had created a test database to check this would work and set it to use the Database General Purpose (Scalable compute and storage options), for once I did it by hand rather than use a Bicep template.

What I failed to realise is there are two compute tiers for this:

• Provisioned — Compute resources are pre-allocated. Billed per hour based on vCores configured​. (The default)
• Serverless — Compute resources are auto-scaled​. Billed per second based on vCores used​.

I just went with the default. What’s the difference?

• Provisioned estimated cost £172.87 per month
• Serverless estimated cost £3.92 per month

One to look out for.

TL;DR Ensure you pick Serverless when using the Azure SQL Database General Purpose (Scalable compute and storage options) or you could spend a lot more than you intended.