Last Monday, after five or six years away from teaching, I helped out on a 1-day, introductory Websphere MQ course. The experience reminded me of the big difference between knowing enough to teach and knowing enough to do.
For instance, at one point, my colleague, Mark explaining how to set up channels between two MQ Servers. From the back of the class, a network admin asked, “Can you have two channels connecting a pair of servers?”1 That’s a perfectly reasonable question, but not one that would have occured to me.
As a developer, I have gained a fairly deep knowledge of certain parts of MQ – those parts that are relevant to my project. As a teacher, however, a much broader knowledge is required to answer all the questions from all the students. The knowledge a teacher requires is so broad, that it would be rare to find a teacher who has actually done in-depth work with every topic discussed in a course like this, leading quickly to the aphorism, “Those who can do, do. Those who can’t do, teach.”
But the converse is also true. Just because you are good at doing something, doesn’t mean you are good at teaching it.
1 The answer is that you can have multiple channels, but only one (active) channel per transmission queue.2 Most systems require only a single transmission queue, and a single channel.
2 Except when running under CICS on z/OS, in which case you can have multiple active channels.