MySQL again is working to derail Oracle’s acquisition of Sun Microsystems, this time with a petition available for signing on

The petition drive is the second such effort to stop the proposed acquisition by MySQL founder Michael “Monty” Widenius, who earlier posted a blog opposing the purchase that he claims was viewed by more than 60,000 users. The deal is currently being held up by the European Commission, which sees antitrust issues in the deal.

Since that time, Widenius has called upon MySQL users to write to the European Commission, which he claims has already received correspondence from more than 400 Oracle customers in favor of the merger.

One of those in favor of the merger is Eben Moglen, founding director of the Software Freedom Law Foundation. While Moglen is traditionally known as a defender of open-source software and of the GPL, he has already written to the European Commission to explain that Oracle’s acquisition of MySQL has little effect on the software’s freedom because earlier versions are available under the GPL. Thus, he wrote, the MySQL community is perfectly capable of forking the code and keeping MySQL free.

But Widenius smells a rat in Oracle’s MySQL plans. “MySQL is causing Oracle sales losses around US$1 billion a year [in lost sales to MySQL and because of heavy discounting when competing with MySQL]. Why would Oracle have an interest to invest in an open-source MySQL long term?” asked Widenius on his blog.

“Oracle has studied MySQL a long time and even offered to buy it twice before, but I have not yet seen the logic or explanation from Oracle that would explain how they can continue to develop and support MySQL without cannibalizing the most profitable part of their business.”

Perhaps in response to Widenius’ earlier anti-Oracle efforts, Oracle issued a statement on Dec. 14 that addressed many of the issues Widenius and others have cited in their arguments against the merger.

In that statement, Oracle claims it will increase spending on research and development for MySQL, and that users will not have to buy a service-and-support contract from Oracle in order to obtain a MySQL commercial license. Oracle also claims it will form both a customer and a storage engine advisory board to help it determine what needs to be done to make MySQL better.

Oracle did not respond in time to comment on this story.

But Widenius is skeptical of these claims, and he calls many of them outright empty promises. He claims that Oracle’s previous acquisition of InnoDB, a company that built an open-source transaction engine for MySQL, is exemplary of Oracle’s intention to slow down innovation and development in its open-source products.

The European Commission meets this month in Brussels to examine the Oracle-Sun merger, and it is expected to make a decision on the matter before the end of the month.