Users with applications that require lots of CPU, memory or input/output to complete operations are good candidates for the new premium tier, Guthrie said. Users with database applications that serve many (over 180) concurrent requests also might find the premium tier better, he said, as would those who have applications with "predictable latency," meaning apps that need to guarantee a response from the database in minimal time.
To get into the limited preview, those interested need to visit the preview features page to request access. Once a subscription has been activated for the preview program, users then should request a premium database quota from the server dashboard or server quistart in the Azure Management Portal.
Microsoft's Azure SQL database already is available in a Web and business edition, which allows users to run relational databases on shared resources. Web edition supports up to 5 GB databases; the business edition supports up to 150 GB databases.
During the premium preview, Microsoft will be offering two database sizes: P1 offers better performance than the Web and business editions; P2 offers twice the performance of P1. P1 is $15 per day and P2 is $30 per day during the preview.
Guthrie also announced on July 23 a handful of other incremental feature additions to Windows Azure. Among them are fully automated, exports of a SQL Database to a Storage account and autoscaling support for mobile service back-ends (in addition to the previously announced autoscaling support for Azure Web Sites, Azure Virtual Machines and cloud services).