The fact that the November release of SQL Server 2005 will ship with the database mirroring feature disabled doesn't seem to be having much impact on users' decisions to upgrade.
Database mirroring is an availability and disaster-recovery technology that creates and maintains a copy of the database -- transferring transaction logs directly to the copy on a continuous basis. In the event of a server outage, the mirror database comes online virtually immediately and with very little loss of data.
Microsoft has touted database mirroring for the past two years in its effort to sell SQL Server 2005 into the very large, enterprise database market, where its presence has been overshadowed by Oracle and IBM.
When Microsoft senior vice president Paul Flessner announced in September that the mirroring feature wouldn't be supported in the initial release, it fueled speculation that Microsoft would lose out in its bid for a share in the enterprise database market..
The issue has had an impact on when users will upgrade. Design process engineer Delton Blackwell, of InPhonic Inc., said, "Database mirroring was one of the major reasons I looked at SQL Server 2005, but now we are not going to use [mirroring] when it comes out. We'll keep using what we've been using for availability -- log shipping and copy and restore."
Blackwell said the announcement that database mirroring is not ready reinforced his decision to wait before going into production with SQL Server 2005. "I can tell you we're not upgrading within the first six months," he said.
He'll be waiting at least an additional six months after the database mirroring function gets the go-ahead before he revisits the question of adopting that feature, too. "I want somebody else to do it first," he said.
According to Forrester Research Inc. senior analyst Noel Yuhanna, holding back on database mirroring may actually demonstrate the soundness of the rest of the release. "The reason they didn't want to have it rolled out was a lack of testing," Yuhanna says. "They were not satisfied with its robustness and reliability."
Although some organizations may be disappointed about the delay, many enterprises that might be interested in it already have alternative availability technology.
"We already have SAN [storage area network]-based mirroring and snapshots," reported Harold LaRoux, systems manager for Penson Financial Services Inc. "So, this was not a compelling feature." LaRoux said Penson will undertake the migration to SQL Server 2005 in the first half of 2006.
Organizations that are eager to begin using database mirroring will be able to activate it in the November release -- or they can activate it now in the Community Technology Preview (CTP) Web site -- using a trace flag option. Trace flags are tools that allow DBAs to temporarily enable or disable a database function. But Microsoft will not support the functionality unless users sign up through their Microsoft customer managers for what is essentially an extended beta test program.
A handful of customers are already using database mirroring in production environments, according to Ilya Bukshteyn, Microsoft's director of SQL Server marketing . The company is looking for more such testers.
"We want to work with those customers to see how they use it and what they need in terms of support," Bukshteyn said. "We wanted more real-world validation before we let it loose." He said the mirroring functionality will be released as an update sometime in 2006.