EnterpriseDB that month also won US$20 million in financing, bringing the total amount of financing it has received up to $28.5 million.

Due to its low support prices, which range from $1 to $5,000 per processor per year, EnterpriseDB competes with other open-source database providers such as Ingres Corp., MySQL AB and GreenPlum Software Inc., which has also developed a custom version of PostGreSQL.

Due to its strong compatibility with Oracle applications, three-quarters of the deployments have been at companies that are heavy Oracle users, said Astor. "They are adding to their infrastructure, building new applications or even leveraging us as a second source," Astor said.

That makes sense to Forrester Research Inc. analyst Noel Yuhanna, who said open-source databases such as EnterpriseDB are making a lot of headway into enterprises' less-critical applications.

"A lot of enterprises are looking at open-source databases. But they are wondering how they can minimize the impact on their applications to keep migration costs down," he said.