Sander Rossel wrote:
Yeah, we don't have the fastest database (50 DTUs), but it's plenty sufficient for everything else.
I ran some testing of our application with Azure SQL some time ago and found it to be very poor for an OLAP style IO bound workload, and probably checking a big index for uniqueness is similar. 50 DTU's on Basic or Standard tier is no more than 200 IOPS - DTU-based purchasing model - Azure SQL Database | Microsoft Learn[^] For us it was better to use a SQL server on an Azure virtual machine, then we could do optimisations like striping the database across multiple smaller (unmanaged) hdd's using Windows Storage Spaces. Nowadays there are probably better managed disk options with SSD's etc to get you a decent IO performance level. Configure storage for SQL Server VMs - SQL Server on Azure VMs | Microsoft Learn[^]