Designing and building an ETL mapping
We are going to design and build our very first ETL mapping in OWB, but where do we get started? We know we have to pull data from the ACME_POS
transactional database as we saw back in Chapter 2. The source data structure in that database is a normalized relational structure, and our target is a dimensional model of a cube and dimensions. This looks like quite a bit of transforming we'll need to do to get the data from our source into our target. We're going to break this down into much smaller chunks, so the process will be easier
Instead of doing it all at once, we're going to bite off manageable chunks to work on a bit at a time. We will start with the initial extraction of data from the source database into our target database without having to worry about transforming it. Let's just get the complete set of data over to our target database, and then work on populating it into the final structure. This is the role a staging area plays in the process...