My Online Doppelgänger

It seems that a few months after I started my IT Journeyman blog that I have an online doppelgänger. That's OK because I'm not the jealous type.

Having skimmed said blog the following post http://www.itjourneyman.com/2010/01/16/data-warehouse-2nd-time-is-a-charm caught my interest and it's essentially a rehash of a few white papers on "pitfalls/mistakes to avoid when building data warehouses". The long and the short of the post is that your first data warehouse will be a failure but don't worry because the second one will learn from those lessons and succeed.

I love to say that this was true but imho its just not that simple. In my travels I've worked on first stab data warehouses that have been blinding successes and also third tries that have had no more luck than their predecessors.

There are lots of elements that go into making a data warehouse project succeed or fail and often the initial expectation setting exercise is crucial. We have to be very careful in determining the criteria of what makes a data warehouse work and what doesn't.

It's a bit like marriage and divorce. Most people would assume that definition a fifty year marriage must have succeeded - but what if the husband and wife were at each others throats for the duration. Likewise divorce after 10 years is seen as failure but what if you've produced a couple of wonderful and well adjusted kids and went your own way amicably. Expectation is everything.

What I can say is that in my experience Data Warehouse projects are difficult and that's why I choose to work in that field and not implemeting somebody elses off the shelf package.

Data Warehouse Projects are voyages of discovery and it's what we learn along the way and not necesarily where we end up that's really important. The problem is that most organisations and most PM's just don't understand that yet.