We stepped through the process of building our data warehouse from start to finish in this book, but did not address having to go back and make changes to objects or mappings we've already completed. This presents some unique challenges as we saw when we alluded briefly to an error that might occur if changes are made to a dimension, but not the underlying table. Let's talk about the features the Warehouse Builder has that will help us with keeping a track of the various versions of our objects as we make changes.
Metadata change management includes keeping a track of different versions of an object or mapping as we make changes to it, and comparing objects to see what has changed. It is always a good idea to save a working copy of objects and mappings when they are complete and function correctly. That way, if we need to make modifications later and something goes wrong, or we just want to reproduce a system from an earlier point in...