It is only by means of good and respectfull discussion that knowledge
and insight will evolve. This post should be regarded as such.

This post is a second reaction to the first article in a series of three
which were written by a highly respectfull thoughtleader in the field
and publisher on the B-Eye-Network; Rick van der Lans. The papers are
titled 'The Flaws of the Classic Data Warehouse Architecture'.

This blog post is a reaction to the first part. It deals with the flaws of the classic data warehouse architecture (CDWA).

Rick signals five flaws which will lead in article two and three to a new architecture. This post is addressing the second flaw.

- My reaction to flaw #1 can be read here
- My reaction to flaw #2 can be read here

Flaw 3 according to Rick
Rick signals the need to do analytics on external data and on datastores that are unstructured. I quote Rick: 'Most vendors and analysts propose to handle these two forms of data as follows: if you want to analyze external or unstructured data, copy it into the CDW to make it availablefor analytics and reporting'. Ricks is wondering why? Unstructured data can be 'handled' on the source and external data can be done by mashup tools.

My reaction to flaw 3
Where are these vendors and analysts that propose to copy unstructured data into the CDW? I do not know them....really I don't. And if they exist - I agree with Rick; don't do it. Especially for the unstructured data I think other architectural choices are more optimal at the moment. But where is the flaw in the CDWA architecture? The CDWA was not meant for unstructured data and still is not. I still do not see the flaw...

But for the external data, I really believe in the years to come that there is still a solid business case of getting this data into your data warehouse. Sure enough - especially for more situational BI - mashups offer very fast time to market for new informational products. Although I believe the securtity issue is not to be underestimated as well as the need to perform analytics on the combinations of internal and - multiple sources of - external data.  

Mashups also need solid architectures.......

So:
- I challenge the notion that the vendors and analysts in data warehousing massively propose to put unstructured data in the DWH. The CDWA was not meant for that purpose. Not a flaw.
- There are solid business cases for getting your external data into your DWH. The CDWA is still a valid approach. Not a flaw.
- Mashups - as is new (BI) technology in general - surely offer new features and promising functionality.