Another Career Advice thread

Question

Hi All, I just have a bit of a career question/rant. I'm hoping some of the more experienced members may be able to guide me.
It seems to me that there are two general "streams" or career paths that a database developer can go down. One can become a BI specialist and work with data warehouses and the ETL processes that come with it, or one can become an expert in transactional processing with high-volume OLTP systems.
I'm at the stage in my career (having been an oracle developer for 9 years) where I'm actively trying to get the illustrious "investment bank contract". However I'm butting my head against what seem to be (to me, at the moment) unreasonable requirements.
I regularly see in job advertisements, statements like "must have experience working in a large commercial environment with 5Tb+ OLTP systems", "experience with High volume OLTP systems essential" and the incredibly restrictive: "Must have prior investment banking experience".
I understand that there is business reasons for wanting to have someone with prior investment banking experience, but my (potentially ignorant) rant is that the coding methodologies for "high-volume" OLTP systems should be the same as "lower-volume" ones. You write the code to the best of your ability and ensure that it is efficient as possible, you keep abreast of the latest additions to PL/SQL and you use all the tools oracle provides as appropriate. As far as I can see, there is no magic wand that instantly makes a programmer "able" to deal with high volume systems.
An example of a question that frustrates me: my friend (a java programmer) asked me "so if you had a large volume web-driven transactional environment and you needed to ensure that the code was running as efficiently, what techniques would you use". I was speechless, I answered that I couldn't possibly know what techniques to use without seeing the architecture and knowing the data. He tried to prompt me for just examples and I hesitantly spouted off things like "pipelined table functions", "query tuning" and "bulk processing techniques" etc. I felt it was like asking a builder "if you had to build a building, what tools would you use?"..."a spade?, a jackhammer? a bobcat?, blasting equipment? Nails? Hammer?" What's appropriate for the job. they're all just tools and it will depend on if you're building a skyscraper or a cubby house for someone's kid....
When I get asked "have you created tables before?" at job interviews I tend to look at the interviewer incredulously and say "yes...." waiting for a follow on question and possibly it comes across as hesitation, when they don't follow up or just say "oh, good" I think to myself "of course I have you moron, I wouldn't be much of a database developer if I hadn't", . But I feel like an idiot putting "have created tables, indexes, constraints" on my CV, in just the same way a builder would feel if he put "have hammered nails, screwed screws and cut wood" on their CV. But apparently it is something recruiters want to see?
...and so my question is: what's so special about high volume systems? What esoteric coding methodologies am I missing? I guess, more to the point: What skills do I need to demonstrate to a potential interviewer and on my CV?
Back to the builder analogy: "oh yes, I'm very good at using a spade and I've used a hammer for over 10 years and know some very good hammering techniques. I'm also have experienced of using a nail gun and a saw." What am I missing here?

Answer 1

Quick one.
With 9 (continuos) years of development, I think you should not be scared of those adverts as long as you have the technical experience. The business or banking knowledge will come on the job. The recruiters post what they have been given from a list of generic requirements. At some places, they will ask you in details. At some, they will not.
On Sector knowledge, it is required in most cases, but if a manager wants to give you a start, then they will not bother once you have the experince. They are stated as beginners. No one was born on the job.
One simple Q&As. The questions are asked to test your ability to respond to requests or tasks. For instance, just answering "Yes" to answer "Have you created a table before", is not enough. I already know that after 9 years, you have created tables, but I would like you to follow it up with an example and a project scenario.
Another reason I would ask you "what is a table" is to test your patience. We always think is is an insult to be asked cheap questions in an interview, but your to-be manager would like to know how you would support and react your users/clients when they are those common simply end-user questions.
High volumes of data requires high efficiency processing. Fora instance, your friend wanted to know what you will put in place to ensure efficiency of a "web-driven transactional environment". One simple clue (out of many) is that the user at the Web front end wants to see the data as quickly as possible. So if I have 1000 rows to retrieve on the screen, I do not want to wait to see the 1000 at the same time. I want to see it 100 rows at a time. So at the database level (of session) I can use FIRST_ROWS to tell optimizer to get things fast, set arraysize to 100, create my screen to show 100 rows and provide a Next button. This is one simple answer to let them know that you have an idea. Later you can research the harder ones.
So, if you see the advert, go for it. Just let them know that you are willing to learn the business sector part of things on the job.
Goodluck