The set-up
You have a mission critical database that uses DB2 V9.7 or 10.1 (or even earlier! We do have customers still running V8). It’s robust, reliable and gives little cause for concern. Upgrading to a new version is going to take your application off-line and is, perhaps, a business risk that is going to be hard to get any sanction from senior management. Best to just let things alone.
There are a number of problems with this scenario:
- Even if you have competent and experienced DBAs to hand, there will eventually be a problem that is actually with the code base itself, rather than the implementation of DB2. If you’re out-of-support, then IBM will not provide an answer
- You will eventually be trapped in a situation where your application needs to be upgraded and / or your OS needs to be, or some other component of your system and this dictates that you must upgrade DB2. You are then under time pressure and you may have to “bunny-hop” from one version to another to achieve the desired and supported level of DB2
- If you do have to upgrade you may find that there are features and functions in the version of DB2 that you use that are deprecated or, worse still, obsolete in the version that you are being forced to upgrade to. You then have to squeeze some application rewrite into the timeframe for a critical database upgrade
The Moral
Don’t let yourself be lulled into a false sense of security; your database may be running without a hitch at the moment but that doesn’t mean it always will (see https://www.triton.co.uk/aint-broke-dont-fix/ for further whinging). Just because the family motor has driven the last 12,000 miles without you looking under the bonnet, doesn’t mean it will do so indefinitely. And if it’s out of warranty….
Furthermore, the latest versions of DB2 include more and more features and functions, and include many performance improvements straight out of the box. Why not take advantage of this?