EnterpriseDB, the commercial company founded on open source PostgreSQL, plans to offer database as an online service through Amazon's cloud computing resources. Beta users are being signed up for a launch of the service in March.

Potential customers, such as a startup firm keeping its computing infrastructure costs down, will be able to sign up for basic database services. "If the [customer's] workload increases, the power of the cloud supports the expansion of the database," said Andy Astor, CEO of EnterpriseDB, in an interview.

The EnterpriseDB Advanced Server Cloud Edition will be run on Amazon's Elastic Compute Cloud, also known as EC2, which is a virtualized environment that can be allocated online in units to external users. In one such unit, a virtual machine with the equivalent of a 1 GHz Opteron processor in CPU cycles is assigned a user, along with memory from a sister service, Amazon Simple Storage Service or S3.

The Advanced Server Cloud Edition is meant to provide online transaction processing services in a reliable fashion. In order to build in database scalability along with CPU and memory scalability, EnterpriseDB entered a partnership with Elastra, supplier of relational database cluster management software that can manage virtualized instances of the database. The size of an Elastra cluster can expand or shrink, based on demand.

An online, Web 2.0 enterprise can contract for Advanced Server Cloud Edition and allow it to scale up if the firm grows rapidly, instead of hiring staff and building out servers and storage in its own data center, Astor said. No pricing has been set for the service. An Elastra example of how it works uses 50 cents per hour of CPU time and $200 per month for a terabyte of storage as examples of pricing, based on the cost of the Amazon services.

EnterpriseDB was founded 2004 in Edison, N.J. It had "just shy of" 200 regular database customers at the end of 2007, up from 60 in 2006, said Astor.