Microsoft releases SQL Azure Database preview

Microsoft has released a free trial of its cloud-based relational database.

The community technology preview (CTP) of SQL Azure Database was made available Tuesday, along with a preview of an SQL Server driver for building PHP applications for the Azure platform.

The Azure Services Platform, first announced at a developer conference last year, is Microsoft's move into the rapidly growing cloud-computing market. As with all cloud platforms, the idea is to provide scalable, hosted services on a pay-per-use basis, running remotely in Microsoft's data centers.

SQL Azure Database, a key component of the platform, is a rival to Amazon.com's SimpleDB. Unlike that service, however, it is a relational database.

Other components of the Azure Services Platform include Windows Azure for running applications and storing data, .Net services for linking the applications to the distributed infrastructure, and Live services for linking Azure to Microsoft's Live web applications.

"With SQL Azure, developers building Web 2.0, ASP.Net and PHP applications can use familiar tools and data models to develop on a pay-as-you-grow, secure, scalable and highly available database service at minimal infrastructure cost," Microsoft senior program manager David Robinson wrote in a blog post Tuesday, adding that "there are really no comparable solutions available today."

SQL Azure's relational data model supports Microsoft and Sybase's proprietary extension to the SQL database language, Transact-SQL. Robinson said there is a high degree of compatibility with SQL Server, allowing for easy migration of business and Web applications to the cloud.

The free trial of SQL Azure Database will last until November, when the service is fully launched. There will be two editions, a Web Edition that stores up to 1GB of data for $9.99 per month, and a Business Edition that stores up to 10GB at $99.99 per month.

David Meyer of ZDNet UK reported from London.