What percentage of SQL Server customers would you guess have already migrated to Microsoft SQL Server 2005 from older versions such as SQL Server 2000? I hadn’t thought about this particular number much in recent months, but the release of the first SQL Server 2008 (code-named Katmai) Community Technology Preview (CTP) at TechEd got me thinking about SQL Server 2005's adoption rates. I’ve been chatting with several people at Microsoft and many other folks who are plugged into the SQL Server community in various ways. Some people have guessed that SQL Server 2005 adoption is currently in the 15–30 percent range, although most people guessed it's in about the 20–25 percent range. The results don’t surprise me too much, although my guess is in the upper end of the range, with "guess" being the operative word. My survey wasn’t a formal, moderated study, and the people I polled hadn't done formal surveys of their own. But as I said, the people I spoke with are pretty plugged into the SQL Server community, so I trust their estimates.

I wonder what impact SQL Server 2008 release plans will have on the large number of customers who haven't yet migrated to SQL Server 2005. Typically, I would expect that we’d soon be entering the sweet spot for upgrades to SQL Server 2005. However, Katmai is now only about 18 months away, assuming that Microsoft ships it by the end of 2008 as promised. I assume that customers with plans to upgrade in the next two or three months will probably stick to with that plan, but what if you didn’t plan to upgrade to SQL Server 2005 for another 6–9 months? That would put you just 9–12 months away from the SQL Server 2008's estimated release date.

Sure, you probably want to migrate to a newer version of SQL Server, but the fact that you’d be upgrading to SQL Server 2005 about two years after it was released suggests you’re more turtle than rabbit when it comes to upgrades. If you've lived without SQL Server 2005 for two or more years, could you wait a bit longer, jump straight to SQL Server 2008, and save a tremendous amount of time and cost by skipping an entire upgrade cycle? I suspect that many SQL Server customers will be tempted to explore that route. Of course, Microsoft will certainly want its license revenue, and you can’t blame the company. I would expect Microsoft to counter that route with various white papers to help evangelize the benefits of migrating to SQL Server 2005, and I wouldn’t be surprised to see Microsoft being aggressive with discounts for its large customers to entice them to migrate to SQL Server 2005 sooner.

I’m curious about what you expect to do if you haven't yet migrated to SQL Server 2005. Will you wait another 18 months and leapfrog straight to Katmai?