Oracle is to meet European Union regulators on 10 December in an attempt to win approval of the planned acquisition of Sun Microsystems, according to reports.
The European Commission is delaying approval of the $7.4bn deal because of concerns that the combination of Sun's MySQL database product and Oracle's products could harm competition in the database market.
Oracle rejected the claim that MySQL competes with its core database software and said it will "vigorously oppose" the Commission's objections.
Oracle said the objections revealed a "profound misunderstanding of both database competition and open source dynamics".
The US Department of Justice approved the deal in August, but had raised concerns over the future of Sun's Java software and programming language, not MySQL.
The UK Oracle User Group (UKOUG) has told the European commissioner for competition, Neelie Kroes, that its membership believes the future of both Java and MySQL will be secure with Oracle.
"Oracle, in terms of strategy and commitment to open source, will provide a secure future for Java," said Ronan Miles, chairman of UKOUG.
"Oracle's record of preserving customer investments and support of open standards would indicate as safe a future for MySQL as any other 'owner'," he added.