Unique identifiers
Holy wars and worse have been fought about unique identifiers for data items and the last word on it has not been written either. The most purist solution is the meaningless numeric sequence and this is usually the recommendation. So why is it that other solutions are adopted more regularly than this simple recommendation?
Well - people get confused in the discussion on unique identification of things, because if you uniquely identify something, wouldn't it be nice to also recognise it. Why have a meaningless number if you can also call me Evert? And this is where people make the mistake. There is a difference between human recognition of a thing or person and what systems need to do with its related records. Every system has different ways of dealing with the names of things and therefore every recognisable identification will have to go through multiple conversions if the item is used in many systems. A neutral number does not have this problem.
The other issue is that things that you can recognise can change. Take country codes as an example. You would think that a country is a pretty stable object, but Upper Volta became Burkina Faso and Birma became Myanmar and then I even did not start mentioning Serbia ... Every time a country changes you have to change the identification of the object in all systems. This can lead to lots of (technical) issues.
My view is that we should allow for both - a unique (meaningless) number and a unique meaningful alias (or set of aliases). The number is the actual primary key, but the alias is what you use in practice on your screen. You can use the alias as much as you like, but when you need to convert, you don't run into technical problems! The more meaningless the identifier, the less discussion when situations change.
The unique identifier needs to be assigned when the object is created and should never change. The best way is to do this via a 'service', an independent component in your system architecture, but this only makes sense in complex large enterprise wide architectures.
Labels: architecture, standards, unique identifiers
Being an Information Architect
I've got a new job, Global Data Architect and the nice thing is that I can define the job from scratch. So that means I will spend a bit less time on management of people & money (the joys of HR and Finance always overtake the content of somebody's job in the middle ranks) and a bit more data management content. It is another way of putting in practice what I have been preaching.
So what do I plan as my new activities?
What I won't do is focusing on building the perfect data model, like the Oil Industry tried with Epicenter (see http://posc.org/ - the good thing is that also these guys have rebranded themselves into Energistics and now focus on standards - so I am sure there will be synergies!).
I also will not rename this blog ;-)
Labels: architecture, new job, standards
Unlocking value
Data Management is a bit of a boring subject to many, But when done well it can lead to massive benefits that you cannot even imagine at the start. An example is the success of the Internet. At the end of the day it is actually a data management success. The
W3C has been very successful in setting and enforcing a few standards on how to address machines in a network (IP adresses), how to exchange information (the IP Protocol), how to name domains (DNS) - and replicate this across the network, and how to publish and link information within these domains (HTML). Everything else after that is now history. Nobody could have imagined the growth of the Internet in the last decade and half.
What it proofs is that we need to agree on certain basics and at the same time need to give the freedom to everything else. Within data management we see people spending enormous amounts of time in trying to come up with the perfect data model, or have endless discussions about how to define a unique identifier, but to me these discussions are usually a bit academic. What really counts is that a decision is taken; a standard has been agreed. It can be a standard which is not perfect (like the Qwerty keyboard); but if it works it will have benefits beyond what it was designed for.
Think about what would be possible with the wide adoption of XML to the same level as the adoption of HTML? Unfortunately agreement on formatting is much easier than agreement on content. Still I can see enormous steps being taken in the Web2.0 world where information from different sources is being mashed together from lots of different sources (e.g. Google News). Imagine what you would be able to do if information within a company could be mashed together automatically, because the information is easily recognised? So it is still worth the effort to spend some time on meta data, because it may lead to some unplanned by-effects beyond imagination!
Labels: meta data, standards, XML
