Now available – Azure SQL Database—preview of read scale-out support in premium service
Following the recent announcement of zone-redundant database support, we're further expanding the power of premium databases and elastic pools by including the read scale-out support. This capability redirects the read-only client connections to one of the automatically provisioned HA replicas, and effectively doubles the compute capacity of the database or elastic pool at no additional charge. This is ideal for load-balancing of complex analytical workloads without impacting the primary OLTP workload.
Source: Azure Roadmap