Allocating a Serverless Database in SQL Azure

Originally posted to:

I’m pretty big on the SQL Azure Serverless SKU. It allows you to scale databases up and down automatically within a band of between 0.75 and 40 vCores on Gen5 hardware. It also supports auto-pausing which can shut down the entire database during periods of inactivity. I’m provisioning a bunch of databases for a client and we’re not sure what performance tier is going to be needed. Eventually we may move to an elastic pool but initially we wanted to allocate the databases in a serverless configuration so we can ascertain a performance envelope. We wanted to allocate the resources in a terraform template but had a little trouble figuring it out.

Traditionally we’ve been using the resource azurerm_sql_database for our databases but this provider is starting to be deprecated in favour of azurerm_mssql_database which has better support for some of the more modern concept in SQL Azure. The documentation is pretty good for it but while there was a min_capacity we couldn’t find an equivalent max_capacity. Turns out you can set the max capacity using the SKU. So we had something like

resource "azurerm_mssql_database" "database" {
name = var.database_name
server_id = var.database_server_id
max_size_gb = var.database_max_size_gb
auto_pause_delay_in_minutes = -1
min_capacity = 1
sku_name = "GP_S_Gen5_6"
tags = {
environment = var.prefix
short_term_retention_policy {
retention_days = 14

This allocates a database with a capacity of between 1 and 6 vCPU that has auto pause disabled. The S in the GP_S_Gen5_6 stands for serverless and the 6 denotes the maximum capacity.