Re: Top Ten Errors In Data Wareousing

} } I claim no particular expertise, but in my opinion a data warehouse } is a *new* thing. Regular databases are optimized for transaction } processing which implies a high proportion of "create or update" } activity and, we would hope, not a lot of full table scans and long- } running queries. A data warehouse is a repository for static data. } The tables may be updated monthly, weekly or daily, but not on-line. } Warehouse tables typically have lots of indexes and may be tuned to } accommodate the most frequent sorts of queries. Some folks even } recommend (horrors!) de-normalizing tables to the extent of, at } least, pre-joining lookup tables to create faster access at the } (to end-users) negligible cost of redundant data(!) in the warehouse. } } The really *new* thing is that warehoused data is intended to be } accessed by end-users so they can get the data themselves and use } desktop tools to turn the data into the information they need. } End-user empowerment -- what a concept! This thing could do away } with the typical MI application backlog (did I see 7 years cited } somewhere) if implemented properly. exactly. j. _____________________________________________________________________________ Jack Parker - Hewlett Packard, BSMC Boise, Idaho, USA jparker@hpbs3645.boi.hp.com _____________________________________________________________________________ Subtlety is the art of saying what you think and getting out of the way before it is understood. _____________________________________________________________________________ Any opinions expressed herein are my own and not those of my employers. _____________________________________________________________________________