Sun is to begin offering certain MySQL features, beginning with some backup functions, solely to its enterprise subscription customers, the company announced this week.
The plan is a shift from the previous strategy of MySQL AB, now a Sun subsidiary, which has traditionally included the same feature set in MySQL Community and MySQL Enterprise.
The move met with harsh criticism from open-source developers, who said it was a sign MySQL is moving away from its open-source roots.
Sun's acquisition of MySQL completed recently, and the company this week delivered a "near final" build of the database's next version. The company has repeatedly promised it has no intention of changing MySQL's culture.
The new strategy will initially affect new backup add-ons such as encryption and native storage engine-specific drivers, which will be offered only to MySQL Enterprise subscribers, according to Marten Mickos, former chief executive of MySQL and now a Sun vice president.
The type of licence that will cover these add-ons hasn't yet been determined, Mickos said; it could be the GPL, another open-source licence or a proprietary licence, or the add-ons could be dual-licensed, as is the case with other MySQL components.
In the meantime, MySQL Community will continue to include native backup functions, Mickos said.
"We are making sure that the core functionality is in the server so that anyone can build their own add-ons — as I am sure many will," he wrote in response to a blog post on the issue. "That's the power of open source."
Other open-source companies, such as Red Hat, also offer free, community versions of their products alongside more advanced enterprise editions that are accompanied by subscription fees for support.
Nevertheless, many open-source advocates, writing on websites such as Slashdot, said the move would create problems for the Community version of the product.
"Another step away from open source. The community edition becomes more of a 'lite' version," wrote Mike Kruckenberg, a developer who has written a book on MySQL administration. "It was harsh to predict this would happen back when the community/enterprise split happened, but now that it has arrived it doesn't seem suprising. It's been a long, gradual, letdown."
Developer Jeremy Cole, a former MySQL employee, said the enterprise-only features might suffer from lack of testing. "The size of the user base for MySQL Enterprise is much smaller than for MySQL Community. That means these critical features will be tested by only a few of their customers," he wrote in a blog post.
Mickos cited a number of companies who offer a split between open- and closed-source, and said the move was driven by necessity.
"If the world were perfect, we would only produce GPL code and we would have a great business that can fund the software development," he said in a post on the Slashdot forum site. "But we have found that the world is not perfect... We need to find a model that allows us to produce a ton of great code under GPL while having the financial strength to do all this."