RE: Job interview questions

From: Iggy Fernandez <>
Date: Mon, 8 Jun 2015 13:37:39 -0700
Message-ID: <BLU179-W62690EB190C92AA532F876EBBF0_at_phx.gbl>

A quick check of shows 46 listings for senior Oracle DBAs ( but only one for junior candidates ( We complain about the lack of senior candidates but we won't give junior candidates a break. If we don't give them a break, the pool of candidates can only shrink. Iggy

Date: Thu, 4 Jun 2015 12:34:35 -0600
Subject: Re: Job interview questions

I'll take a whack here too...

I think the intent behind asking obscure technical questions is to initiate a conversation on a very specific technical topic. With luck, the seemingly trivial question can reveal not only that the candidate is fluent on the whole topic, but also something about how they relate to other people and how they might fit in.

For example, asking a question such as "What is the common nickname for an 'inconsistent' backup?" (answer: "hot" or "online" backup) can lead to several great follow-up questions about how backups are captured and why they're recoverable. For example, if they get that right, you can then ask if simply restoring an "inconsistent" backup is sufficient to open a database successfully, or whether additional steps are necessary (i.e. "no" and "recovery rollforward with redo logs" are good follow-up answers). If you have a suspicion that the candidate is snowing you, then you can ask whether datafiles are "locked" against writes while they're being backed up or not, and find out if they have some whopping misconceptions about how Oracle works.

Getting these answers correct or incorrect is not really the point; lots of good people get them wrong. In real life, people can google for these answers.

But how they interact with you during this conversation is very revealing. Whether they know this stuff or not. Whether they freeze up when faced with a complex problem, or whether they grow more engaged and animated at the challenge. Whether they actually get angry when confronted with their failure.

If they know their stuff and answer correctly, again it is illuminating. Some get cocky and rattle off the answer in an almost arrogant fashion. Some are undoubtedly arrogant about it. Some are just matter of fact and cool and collected. Maybe you want arrogant. Maybe you don't.

Of course, the follow-up questions can go another way, into personal experience and war stories. "What is the scariest situation you've ever encountered?" Every infrastructure person has been scared stiff at one point or another, and if they haven't, then they haven't done anything. It's not fair to ask someone about their failures during an interview, but I think it is quite kosher to ask someone about when they were most frightened.

So, an interview isn't merely a series of trivia questions to be scored, summarized, and averaged. No doubt scoring correct answers is useful, but there's much more. Good questions encourage the candidate to reveal something about their own characters.

    On 6/4/15 12:02, Iggy Fernandez wrote:


          absolutely loved the blog post recommended by June and read
          every word of it.

            remember the interview at which I could not answer the
            question "how do you enable block change tracking in a
            database?" (The answer is "alter database enable block
            change tracking,") I don't want to work for Yahoo any more.

        I remember the time when I could not get hired at Google
          because I could not solve a riddle.
          I don't want to work for Google any more.

          I remember the worst interview of my life when the hiring
          manager walked me to the door when I correctly answered a
          simple question about redo logs (he was wrong).
          I don't want to work for [let me protect the guilty] any more.

        Personally, I don't think the absence of particular
          technical skills matters that much. They can always be learned
          by a motivated learner. I would prefer a motivated learner
          rather than a really knowledgeable person with a bad attitude
          or who never got anything done.

        The person's work history and the  opinions of his/her
          previous co-workers and managers is the information we need
          but we don't have it. Only some LinkedIn accolades like "his
          unique skill taking on abstract blue-sky corporate objectives
          and converts them into specific actionable goals".

        The company takes a big risk
            by hiring me (how can anybody really evaluate me in a few
            hours?) but the bigger risk is the one I take in joining a
            company. The question I want to ask (but never do) is "Who
            am I replacing? Why did they leave? What did they not like
            about the job? Can I call them?" Also, "Do you believe in
            work/life separation?" Also, "Do you ruthlessly lay of
            employees like [let me protect the guilty] in order to
            achieve the quarterly earnings target?" Also, "how crazy is
            database administration in your company; is it as
            wonderfully wonderfully (wonderfully) smooth as eBay and
            Intel or as crazy and terrible as [let me protect the
            guilty]." Also, "Do your team members go to NoCOUG
            conferences and, if not, why not?" Excuse my NoCOUG plug.


        I would hire a young person
            or experienced person and teach them all I know but
            companies don't like to do that. They do like to complain
            about the shortage of good DBAs though. I once hired a
            person with very little Oracle or DBA experience and asked
            him to work on certification. He completed certification
            (8i) in nine months and, 15 years later, is still with the
            same company as a glorified Oracle architect.

        For every technical hard-to-answer question somebody asks
          me that I cannot answer (e.g. how do you fix wait event "X" on
          Exadata 12c Release 2), there is a technical harder-to-answer
          question that I can ask them that they can't answer. My
          favorite is "What is serializability of transactions. Does
          Oracle provide it?" (the answer is "No"). with
          two additional links at the bottom.

        I have never met a DBA who could answer the question "what
          are the deliverables of the DBA role?" to my satisfaction.  How likely is it that I will work
            on the deliverables if I cannot articulate them? Installing
            security patches is not a deliverable, but a task. I would
            hire a SQL Server DBA who could give me even a partial
            answer and was a quick learner.

        I have often been rejected for jobs because I was not
          competent enough at that time. I have achieved all
          those competencies by this time but, strangely enough, I no
          longer want those jobs any more. There are jobs out there that
          I want but they won't hire me because I am not competent
          enough at this time. C'est la vie.

        Just some random thoughts of
            course. Kindest regards and best of luck finding and
            retaining great people.


            Date: Thu, 4 Jun 2015 18:29:19 +0200

            Subject: Re: Job interview questions







                an interesting post I recently read:




              On Thu, Jun 4, 2015 at 5:50
                PM, TJ Kiernan <>

                      For those of  you who have
                        conducted job interviews, what sort of questions
                        have you found to be effective in evaluating a
                        candidateís skill level?  Iíve started a list
                        that consists of some Oracle trivia and some
                        open-ended work habit/personality type
                      Incidentally, I know of a
                        Oracle DBA job opening in Omaha, NE.  Please
                        contact me off-list if youíre interested in
                        knowing more.


                                  T. J. Kiernan
                              Lead Database

                                  Pharmaceutical Services

                                  P.O. Box
                                  407  Boys Town, NE 68010

                                  Direct: (402) 965-8800 extn.

                                  Toll Free: (800) 546-5677 extn.



Received on Mon Jun 08 2015 - 22:37:39 CEST

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