Where can I find the Oracle Home?... type in linux: echo $ORACLE_HOME
How can I get my sql statement again in SQL*Plus?... type in SQL> ed (but make sure that you did in linux for ex.: export EDITOR=vi)...
I can't see the employees table when I'm logged in as SYSMAN?... did you put hr.employees in the select or do you have a public synonym...
Why doesn't Enterprise Manager/iSQL*Plus work?... did you start the services/processes (emctl)...
I can't login into the database and I'm sure I started it!... is your listener running...
What's a public synonym?...etc.
The last two days I had to teach an Oracle DBA Workshop in the school I graduated 7 years ago.
In the beginning it felt strange to be there... but the "school-feeling" was quickly adopted again, although hearing "meneer" (sir) instead of "Dimitri" is funny in the beginning ;-)
I really liked to teach although it was different then I imagined. You must be well prepared and to serve these guys (and one girl) asks a lot of energy... I hope they learned something useful for their later career, but mostly I hope they enjoyed the lessons. At the end, doing "Oracle" must be fun!
Giving a course once and a while can be good! Everybody needs to learn how to work with something... in the beginning of this post I included some questions I got during the exercises. I forgot that some things are not that evident when you're new to Oracle. I do things just like that, because I'm used to do it, but having these questions obliged me to think again why you need to do it. When I was explaining the "why?" and "how?" I remembered that it's important to know what you're doing. And like Tom Kyte says so often, things change!
The practical side of the course was very Enterprise Manager oriented. I was really surprised that EM10gR2 is so much better than before (9i, 10gR1) and has so much possibilities! Almost all DBA things are now possible with EM. The only thing I didn't find directly, and I think that is not yet fully included, is the auditing part. You can do some standard auditing, but I didn't find the possibility to do in dept Fine Grained Auditing...
It would also be nice if you could make EM more your "own"; adapt standard reports, show/hide regions etc. I know that 11g has some more advanced things! I look forward to see it...