Sybase ASE has only a fraction of the database market share held by Oracle, IBM and Microsoft, but it is widely used by financial institutions. SAP noted this in its announcement, saying its ERP customers will now get to use the same database "that powers Wall Street."

Future versions of SAP ERP will be "certified out-of-the-box" with Sybase ASE releases, SAP said. In addition, Sybase ASE's life cycle will be "fully synchronized with SAP maintenance policies to simplify release and deployment planning for customers."

The combination of ASE and SAP's business software will mean customers can deal with a single company "focused on efficient business operations and on providing attractive licensing and maintenance terms and conditions," SAP said.

It's not quite clear how much customers could save buying ASE compared to Oracle, although such estimates are hard to pinpoint, given the heavy discounting off list price that often occurs in software contract negotiations.

Also, there's no telling how Oracle would respond in terms of pricing or customer incentives, should SAP manage to siphon off a significant amount of database revenue.