What's a Data Warehouse for?

Peter Nolan, esteemed DW'ist, writes in the venerable dwlist mail list (subscribe, archive) what he thinks a data warehouse is for...

Instead of making the right data readily available to the people who really need it with tools they can really use to do what could make a really big difference to the business we gave everyone a pretty dumb browser interface and we gave lots of people access to data that they have barely any earthly use for other than to fill up their 8 hour working day fiddling around with it. Oh, but these dumb web interfaces have nice pretty charts and buttons and things and that makes all the difference.....hhhmmmmm.

...in any organisation, there is only a very limited set of decisions to be made which drives only a very small number of 'questions' compared to the set of 'all questions that could be asked'. If a DW project concentrates on 'the set if possible questions that will make a major difference to the organisation' and collects the data for that rather than 'any possible question' and collects the data for that, the project is far more likely to be successful.

More of his thoughts along these lines are in an Intelligent Enterprise article from 2001.