This probably falls more in the DB2 newbie category, but I suspect I may have some readers who are DB2 newbies or at least not veterans.
I have generally been a bit disappointed on the information coming out of IBM on supporting Commerce databases. I also meet clients who don’t believe they need a dba or that they can hire someone out of college or with minimal database experience to fill such a role. In my opinion, any reasonably sized Commerce implementation needs a DBA, and unless that DBA has years of experience with DB2 (or Oracle as the case may be), and at least a year of experience supporting Commerce databases specifically, then it’s going to need to be a full-time dedicated DBA.
DB2 GUIs Suck for a variety of reasons - use the command line.
Several times I've figured things out in my career and thought "how did I ever call myself a DBA without knowing that?"