We have a database that is used quite heavily (almost 100% of requests are selects), and now database becomes a bottleneck.
We were looking for a solution that would let us scale this database out (horizonally) and load balance request across multiple instances
In perfect scenario what we are looking for is a way to dynamically add-remove instances (in a way similar to how you could scale instances of Azure Web App).
So far, the best solution I found is 'Read scale out using read-only replicas': https://docs.microsoft.com/en-us/azure/azure-sql/database/read-scale-out. And this looks like a perfect solution, the only problem is I don't see how I could add more replicas there?