Customers at the MySQL conference this week said Sun Microsystems' acquisition of the database company, could increase MySQL's credibility among senior IT decision makers still skittish about using open-source software.

There were some, though, who feared that ownership of MySQL by a traditional IT vendor would diminish growth in the community of MySQL developers, who provide a regular stream of patches and new features for the database.

"The main downside is that the community might reject it [Sun's purchase of MySQL]," said Yuriy Demchenko, a database administrator and Web applications developer at a large Canadian telecommunications company. "We'll see if the community continues to grow at the rate it has."

Demchenko said his company, which he did not want identified because he is not authorised to speak for it publicly, runs primarily Oracle and IBM's DB2 databases, but his department uses MySQL for "semi-official startup projects" that sometimes end up running in production. He uses the community edition of MySQL "because it's free."

The upside of the acquisition is that it will make higher-level executives at the carrier more comfortable with MySQL because it is owned by a big, stable company, Demchenko said. His company already uses Sun servers.

Sun closed its $1 billion purchase of MySQL in February and is hosting its first MySQL user conference this week in Santa Clara, California, where it released a near-final version of MySQL 5.1. It has been at pains to emphasise its support for open source and similarities in the companies' cultures, despite their vast difference in size.

"Sun has a relatively enlightened attitude to open source, so I don't see [the acquisition] affecting the community too much," said Steffen Higel, a systems engineer with online gaming company DemonWare, which is using a version of MySQL 5.0 to serve up games like Call of Duty 3.

DemonWare switched from the Ingres database to MySQL about a year ago because it found Ingres "terrible" in terms of support and performance, and because Higel and his colleagues had experience with MySQL at a university, he said. It began with the free community edition and switched to a paid subscription after DemonWare was acquired by Activision, Higel said.

He is happy with MySQL but would like more back-up capabilities, which are not due until MySQL 6.0 later this year. Sun said this week it would delay the final release of MySQL 5.1 by up to three months, but Higel said that's "not a huge deal, there's nothing show-stopping we need."

Lionel Beaudet, technical manager for the French division of Virgin Mobile, is more worried by Oracle's acquisition of Innobase than by Sun's MySQL buy. Innobase makes the default transactional storage engine for MySQL, and the Oracle deal has created some uncertainty for MySQL users.

MySQL is developing a storage engine for MySQL 6.0, called Falcon, and partners are developing others. Virgin Mobile will test Falcon to see how it performs in case it needs to make a transition, Beaudet said. Marten Mickos, the former CEO of MySQL and now a Sun senior vice president, said MySQL recently renewed its licence with Oracle, though he would not say for how long.