So, after many months of anticipation and “technology preview” presentations at various conferences, IBM have finally announced the start of the beta process for the new version of DB2 for z/OS. The product that went under the cunning codename of “DB2 X” has today broken cover as….DB2 10 for z/OS (geddit?), with the beta code being made available to selected customers from March 12th 2010. No official word on General Availability dates as yet, but I think it’s safe to assume that if all goes well with the beta, DB2 10 will be released sometime during the next 12 months or so.
As always, this new release of DB2 contains a large number of enhancements and new facilities, and I’ll be covering some of the major ones in future blog posts. But before we get into that, I want to concentrate on two specific aspects of DB2 10 which are pretty unusual as far as recent releases are concerned: skip migration and performance regression.
Traditionally, IBM has only supported migration to a new release of DB2 from the release immediately preceding it (you could only migrate to V8 from a V7 subsystem, for example). Up until now, the only exception to this rule was DB2 for z/OS Version 7, which supported direct migration from both V5 and V6. There were good reasons for IBM to offer this facility in 2001 when V7 became generally available, as “Y2K fever” had prevented many V5 customers from being able to migrate to V6 according to their usual timescales. Skip migration was a great way of helping those customers to catch up and climb back onto the upgrade bandwagon, but it wasn’t without its downsides: it required IBM to expend significant effort to develop and support, and left customers with twice the number of pre-requisites to manage and new function to absorb. Whenever the subject of skip migration came up in conversation since then, several of my IBM friends were heard to mutter dark oaths, with phrases such as “over my dead body” and “never again” being quite common.
Well, never say never. DB2 10 for z/OS will support skip migration from V8 as well as from V9, and for very similar reasons to those that convinced IBM to support the jump from V5 to V7 way back in 2001. Despite DB2 9 containing some very attractive new function and being Generally Available for nearly 3 years now, the recent global economic downturn has seriously impacted IT budgets and many customers still find themselves running DB2 V8 (or even earlier releases).
So….does that mean that everyone on V8 today should wait and go directly to DB2 10? No! As I already mentioned, skip migrations have significant downsides in terms of increased complexity and risk, and don’t save nearly as much time or money as you may think (you can expect a V8 to V10 migration to save somewhere around 20-25% when compared to separate V8 to V9 and V9 to V10 migrations). If you’re on V8 today, the chances are that you’re missing out on some pretty significant business benefits that DB2 9 for z/OS could provide (see my white paper on DB2 9 Business Value for more details). Given that most customers won’t be looking to move to DB2 10 for another 18-24 months at the very earliest, there’s a good case to be made for established V8 sites to think about moving to DB2 9 now.
So….who is the skip migration actually going to benefit? If you’re brave or unlucky enough to be running on V7 (unsupported for well over a year now) you’ll hopefully be planning an upgrade to V8 very soon. V8 is a big pill to swallow, and will probably keep you busy for the next 6-12 months while you roll it out across your various environments. Once you’ve done that, you’re going to be nicely placed to take advantage of the skip migration and go directly to DB2 10. Likewise, if you’ve only just completed your V7 to V8 migration project and are unlikely to get management approval for another migration to DB2 9 so soon after the last one, you may want to consider staying with V8 for now and migrating directly to DB2 10 during the next 18-24 months.
Whichever path you take, make sure you’re getting some good advice on the pros and cons, and go in to the migration project with your eyes open. Don’t underestimate the effort involved in a skip migration, or the “culture shock” for developers and support staff asked to take on two releases worth of new function in a single, large, indigestible lump.
That’s it for today. In my next post, I’ll pick up on the topic of CPU regression during version upgrades, and share some of the good news that DB2 10 promises for those poor souls who have to justify version upgrades.