Sun is to offer users of its high-end Ultrasparc servers 12 months free subscription to Oracle's flagship database, in a bid to encourage users to upgrade to the latest Sun hardware.
Oracle said more organisations run its products on Sun hardware than on alternative hardware platforms.
The Sun move might spark a wider price war as hardware and software suppliers bundle products in a fight for market share.
Industry analysts are advising users already running Oracle on Sun servers to revaluate their options and use the offer as leverage in renegotiating licences.
David Bradshaw, principal analyst at Ovum, urged Oracle users on existing contracts to contact Oracle to see if they could also benefit from a reduction in annual maintenance costs.
Rob Hailstone, research director at IDC, said it was also a good time for users to re-evaluate their hardware.
With Sun's "DB for Free" promotion, an Oracle Database licence is free with the purchase of first-year maintenance on the Ultrasparc IV and the Ultrasparc IV+ processor-based Sun Fire servers.
Sun chief executive Scott McNealy and Oracle chief executive Larry Ellison unveiled the offer last week along with a set of initiatives to entice Oracle users.
Along with the database licensing, users will be offered a new upgrade programme for Oracle Real Application Clusters on Sun hardware.