Monday, April 29, 2013

DBA Part 4 Architect and Builder


Another metaphor, perhaps even a labored one!  


DBA’s are Designers and builders.  Even if you have a system in place it needs renovation or perhaps is close to end of life.  A DBA always is looking to improve things.  Tweaks to make things faster, more safe, more reliable, more available.


There are two key ways DBAs look at the database world.  One is very application centric and deals with tables, columns rows and relationships.  The other is very infrastructure (Servers, disks, networking) centered revolving around GHz, gpbs, GB and so forth and so on.

Again the DBA must know the business and the application.  Working with a Business Analyst (or being one himself as I am a BA too) the DBA needs to learn as much about how business works in order to know how to best store the data in tables.   Now, in many shops programmers do this task, and some even do a good job.  But in most shops that have a DBA, the DBA is brought in to bless the data design in ER diagram form before being tasked to actually build it.

In an earlier installment of this series I mentioned the term Normalization.  This is the time in the development life cycle (SDLC) that the DBA will employ normalization the most.  Looking at the data that the company wishes to store element by element, seeing how it all relates and then weeding out redundancy and dependency until all that is left is a lean, mean, data storage machine.  Or database.   This takes time, thought, printouts, many hours of staring at printouts,  a few key moments of head hitting wall, and then more thought.

Once the design is done (assuming no emergencies are currently under way, no new software is being deployed, all maint tasks have been done properly and there are no end users with pending query requests lurking about) , the DBA needs to meet with the development staff and explain the design.

I once had the misfortune of designing a very clever schema that was very powerful, flexible and fit the need just right, but didn’t have the time to explain it.  My developer (who happened to be, in this case, my boss’ boss) claimed to understand the design.  I assumed he was right and moved on to other DBA like tasks (napping perhaps or donut eating) and left said developer to their own devices.  Fast Forward to 3 days before go live.  There was no code review, no testing, no nothing.  The developer was in my office hot under the collar because he couldn’t get something to work right.  I pointed out that it was clear he misunderstood the design, and had put in place many hacks and workarounds to my elegant design, and that was causing unneeded complexity and was the cause of his bug.

This revelation went over like a ton of bricks to which he told me
1) that he “Hated me in the marital way” and
2) would NOT ever fix it the right way because he had invested too much time in the wrong way.

Lesson?  Always take the time to talk to your developers, even if they claim to understand.  To you developers in the audience, please make sure you request a walk through, and understand it fully.  This database went into production, caused so many issues that I re-redesigned it, handed it off to proper developers EXPLAINED it fully, and now there is a much better application sitting on top of this awesome database.  This bug was my fault because I did not make sure that the user of my design understood it clearly before setting off.  When your DBA explains things to you and tries many ways to make it clear, please realize he is just trying to avoid any missteps.  

DBAs also must make sure that everything that the database is sitting on meets the needs of the applications that rely on the database.

This means that the DBA has to walk down to the guys who deal with nuts and bolts.  In this unsavory world people do actual physical labor including, but not limited to, lifting heavy metal boxes, and plugging cables into them.

Most end users aren’t brave enough to even talk to these people, and for good reason, they are scary!  The DBA has to make sure to not only talk to them, but *gasp* develop a great working relationship with them.

While wearing this hat, the DBA must use his knowledge of the applications, the company and how databases work, coupled with his knowledge of server hardware, operating system, networking and storage to help to design a solution that meets today’s needs AND will cover future growth.  

Yup, DBAs also must look into the crystal ball and predict the future.  I did that with a few key metrics on data growth, transactions per time period and looking at the sales pipeline and talking to the execs in Sales as well as the CEO to make sure I understood where the company was going.  If your DBA wants to talk business, indulge them, educate them, help them to understand what is important to your business.  They are just trying to be as educated as possible so that they can make good decisions.

Armed with this, a plan (or three) are developed.  First there is the “Money is no object” plan.  This one is fun because you can look at all sorts of exotic technologies and put together the killer system.  There is the middle of the road that gives you nice features but costs less, and then the bare bones, what can you get away with and make due with.

Once the plans are in place, the DBA will then have to defend decisions and assumptions, and therefore must be armed with data (ironic?) .  Being armed with data is one thing.  Another is being able to make cogent arguments that hit at the core.  Always hit them where it counts, in the money belt.  Yes you are asking to spend a lot of money, but what happens if the data isn’t available, what happens if it isn’t retrieved as quickly as possible, what happens if the company grows faster than expected and then they have to spend EVEN MORE money on a solution that they could have had in place to start with.

Business people speak in terms of money. DBAs don’t.  DBAs need to, but they simply don’t think that way.  Remember when speaking to a DBA about this wiz-bang infrastructure that he has planned that he does indeed want the company to succeed, and wants to do so without spending too much money and without working too hard.  We are people too, and I do realize every penny I spend on a new SAN means one less penny for my pay check or bonus!

This is, in my opinion, the most fun a DBA can have.  The work is almost all theoretical, and has no current impact.  Nothing breaks when pencil hits paper, there is no down time, no risk.  Just research into what is, and what should be.  Both in the technology realm, and in the business realm.  If the DBA seems carefree and smiles, chances are there are no looming emergencies or maintenance windows AND he is busy designing the next generation for the company.  That is a good time for a DBA.  At least for a brief moment when a possible issue that they thought of today is not currently handled, and that will cause another sleepless night!

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