When I started working with SQL Server, the versions came a strange paces. Three years between v4.2 and v6.0, but less than 1 before v6.5. Then two years to v7, one more to SQL Server 2000, but five until SQL Server 2005. After SQL Server 2008, we've moved to a 2-3 year cycle, but I can see that accelerating a bit more as SQL Server vNext looks like it might come in 2017, a year after SQL Server 2016. Since much of the code is released to Azure first and exercised there, I could see us getting on premise releases coming every 1-2 years in the future.

Overall, I like this pace. We can see changes coming to the product on a regular basis and enhancements that I can choose to implement or not. We no longer have to wait years to get an enhancement or evolution of a feature. We always have the choice to upgrade. Many of us won't, but that's OK. Perhaps we'll use new features in new applications, and learn how they might make the case to, or not to, upgrade existing instances.

There's a flip side to the rapid releases and enhancements to the platform. Many of our organizations expect a database server to last for years. We invest plenty of resources in building these database servers, and I think many managers and organizations expect they will be in service for at least five, and maybe ten, years or more before they are decommissioned or perhaps upgraded. I know there are still plenty of SQL Server 2005 and 2008 instances (probably not 2000) that are being used on a daily basis with no plans to replace them.

This means that as the developers and DBAs that work with SQL Server, we will likely be supporting a wide range of versions in the future than ever before. Even if you started a company two years ago with a SQL Server 2014 instance, I'd guess you might have a few more now, perhaps some SQL Server 2016 instances. In two years you might have 2014, 2016, and 2017 (assuming vNext becomes SQL Server 2017). In five years, perhaps you'll have five versions to support. I know there are people in that situation today with 2014/2012/2008R2/2008/2005 instances in production.

There was an announcement this week from Microsoft. They are now offering SQL Server Premium Assurance, which will give you 6 years of support after the 10 you ca now get with Extended support. Certainly there are restrictions and costs, but I expect that there will be some large organization that think it's worth paying this to continue to use older versions as long as possible. After all, this is a platform, which implies some level of stability.

That doesn't solve the knowledge issue and need to keep staff around that understand the platform, but with all the education and knowledge available from places like SQLServerCentral, perhaps supporting multiple versions isn't a bit deal.