Sybase is preparing to unveil an update to Adaptive Server Enterprise, its flagship relational database, that will use virtualization technology to let users run a single instance of ASE across a cluster of servers.

The clustering support could offer better reliability and protection against system failures, while enabling users to put ASE on multiple low-cost servers instead of larger and more expensive ones.

The new version is due to be announced later this month, according to Sybase officials, who wouldn't disclose any details about the technology. But a 45-page presentation about the update, which is referred to in the document as the ASE 15 Cluster Edition, has been posted on the Web site of Sybase's Polish subsidiary. A data sheet about the Cluster Edition can also be found on Sybase's main Web site.

In addition, advance word of the upcoming release has filtered out to some Sybase users and business partners, who have made it a topic of discussion on database forums.

The cluster plans weren't a huge secret to begin with. Sybase officials discussed them at the company's TechWave user conference in August 2006, saying then that the vendor expected to add a shared-disk clustering capability to ASE 15 in the first half of last year.

ASE 15 Cluster Edition will run on 32- and 64-bit versions of Red Hat Linux and SUSE Linux, as well as Sun Microsystem's Sparc-based Solaris systems, according to the documents posted online. The database will support up to 32 server nodes sharing a single storage-area network.

Sybase's shared-disk architecture appears to be more similar to Oracle's Real Application Clusters technology than so-called shared-nothing cluster architectures, such as the ones supported by Microsoft's SQL Server or MySQL AB's namesake open-source database.

Sybase has long lagged behind the top three relational database vendors: Oracle, IBM and Microsoft. But ASE is still winning customers, many of them in the financial services sector or located in Asia. Sybase officials said last month that the company added almost 1,200 new ASE customers last year, up 20 per cent from the number added during 2006.

The vendor reported in January that for 2007 as a whole, its revenue topped the US$1 billion mark for the first time in seven years. But Sybase is being pressured by a Wall Street hedge fund that is its second-largest investor to either buy back stock, spin off some of its faster-growing divisions or put itself up for sale altogether.