Azuer provides multiple Servie level options to choose for your database(s)s depending on number of databases/ Size/ CPU/ Number of Sessions/ Number of Connections to the database.
As the number of database you want to host increases you have more challenging task to find optimal solution.
Following are the pointers which an be used for analysis:
* Azure SQL Database benchmark overview: https://azure.microsoft.com/en-us/documentation/articles/sql-database-benchmark-overview/
* SQL Database Service Tier and its limits: https://azure.microsoft.com/en-us/documentation/articles/sql-database-resource-limits/
* Elastic Pools and Limits: https://azure.microsoft.com/en-us/documentation/articles/sql-database-elastic-pool/
* SQL Database Pricing: https://azure.microsoft.com/en-us/pricing/details/sql-database/
* Azure Database capacity is always measured with DTU, it is good to understand the DTU and eDTU (eDTU is the term used for Elastic pool DTU): https://azure.microsoft.com/en-us/documentation/articles/sql-database-what-is-a-dtu/
* Interested to follow all new articles: https://azure.microsoft.com/en-us/documentation/articles/?product=sql-database
* Azure health status: https://azure.microsoft.com/en-us/status/ This link can be used to check the status of Azure environment in each region.