Microsoft Wednesday added SQL Server Data Services to its freshly introduced lineup of online infrastructure services for corporate users and said it is registering users now for the beta.

Ray Ozzie, Microsoft's chief software architect, disclosed the new service during his keynote address at the company's annual Mix conference in Las Vegas. He said SQL Server would be used to create a database in the cloud to support all types of applications.

"This highly scalable database service will bring the benefits of SQL Server for developers into the cloud," said Ozzie.

Ozzie's announcement follows Monday's kick off of a beta program to introduce online infrastructure services around Exchange 2007 and SharePoint 2007 to corporate users of any size.

Microsoft also said it will launch a beta of Office Communications Server (OCS) available in the second half of 2008, called Office Communications Online, to round out its suite of online services, which will also include Web-based conferencing via Live Meeting.

Microsoft said SSDS will be targeted at small and midsized businesses to help reduce costs, corporate users to support applications and sharing data, and at developers and service providers.

Microsoft said some of the use cases would revolve around storage of archival or reference data, storage of large amounts of structured or semi-structured data using a flexible schema, run applications on the Internet that can tolerate some latency, and support for business needs such as HR services, healthcare records management, data archiving and Internet facing applications like social networking and picture sharing.

Microsoft said the database server will be exposed via Simple Object Access Protocol and REST APIs, which will allow the creation of authorities, containers and the creation, update and deletion of single entities.

Users will be able to upload and query data and access large unstructured data objects using a URL.

Users will pay for each "account" they open and each will be accessed using a unique Windows LiveID. Microsoft did not announce pricing for accounts.

SSDS will support a text-based query language that follows the LINQ pattern for C#, Microsoft said.

Microsoft will offer security at the account, authority and container levels. Each authority is secured by a single "secret key" granting read/write access. In addition, each container within an authority is secured by its own single "secret key" granting read/write access. User also can make the contents of containers read-accessible to a general audience.