It seems only reasonable that what one person can do, others can learn. On the other hand, taking people through training does not usually result in the creation of great new database administrators (DBAs). It often appears as if those who are exceptional at the craft operate at higher levels as they dive into a problem. Can training alone provide folks with the attention to detail, the urge to keep digging, or the ability to recall minutiae that allow them to rise from simply holding the DBA title to becoming someone who is a great DBA? Or must the genetic potential exist first, and then one might fall into the DBA occupation and astound those around them. It is very hard to say with any degree of certainty whether great DBAs are made or born; yet again the battle between nature and nurture arises.
Certainly, there are many aspects of assembling and managing databases that can be trained. Obviously, to be in the running for qualifying as a great DBA, one must have attained a high level of proficiency in doing the tasks required by the DBMS worked on, and in comprehending the functioning of the DBMS components and internals. These things are skills that should be acquired readily via training. In today's world, quoting chapter and verse on any specific detail is not a requirement, as almost anything is easily looked up on the web. But it should be required that one have a good handle on when to stop beating one's head on the wall and actively reach out for needed help.
Truthfully, many DBAs often look like they are simply hanging around. I have heard people referring to DBA as an acronym for "Do Barely Anything." But that view alone means little. Occasionally, you may run across someone in the DBA role who is a waste of space. But great DBAs can present a very similar exterior, as they are digesting several new thoughts after having attacked and overcome the latest performance or space issue and started considering aspects of a seemingly simple query that isn't performing as anticipated. Distinguishing between the two, a wasted versus a valuable resource, is best determined by looking at the overall picture. Do the DBMS-related performance issues get addressed quickly? Are those DBMS issues generally non-recurring? (Fixing the same problem over and over again can be a very bad sign.) Does development and maintenance staff get thorough help when they request assistance from the DBA? Might your staff even mention again and again how they learn so much from the DBA? Does your DBA see change as a challenge or something to be prevented at all costs? Do you see the passion towards data, problem-solving, and the DBMS in the DBA's eyes and actions?
How can you tell if someone has what it takes to be a great DBA? There may be obvious articulations with expressed traits dancing around those of the very obsessive compulsive, exposing the thin lines between obsession and insanity. One of the best DBAs I worked with was a list person. She had a list for almost every task she needed to perform on a regular basis. And the last item on every list was to update that list based on any new knowledge gained through that last iteration. She always followed her lists faithfully. The lists also greatly helped new staff or backup personnel get up to speed, functioning quickly and effectively during her absences. The signs, however, are sometimes hidden and are only truly appreciated as a chaotic database environment transitions into a calm and smooth running set of processes. No sign alone can prove things one way or another, sometimes crazy is simply crazy; the only true proof is in a track record of results.