Most of you probably are already familiar with my 12-step methodology for designing, building and maintaining data warehouses. ETL vendors offer products that consolidate, transform and cleanse legacy data en route to data marts, data warehouses or OLAP cubes. Once warehoused, the integrated data is available for analysis without requiring access to the operational databases it was derived from.
Users access a copy of the original data.
Also, not everyone has even built a data warehouse yet. Excepting for stock market prices other data are not expected to change at short inervals. For fast changing data some form of trend graph generation as done in distributed control systems may be thought of with data trends being backed up in floppys. My comments are not from any expert knowledge of software development, myself being a novice in software development. I am interested in technologies avaialable for data warehousing.