Spreadsheet Data in the Data Warehouse
It has long been known that raw data entering a data warehouse needs to be transformed. In this regard, data coming from a spreadsheet is no different.
Why, though, should data coming from a spreadsheet be transformed? And doesn’t transforming the data change the value of the data? And isn’t the owner of the spreadsheet the only person that is allowed to change the value of data?
The answer is this: for the purposes of preparing spreadsheet data for a data warehouse, transformation does not truly violate the principle that only the owner of the spreadsheet should be allowed to change data.
In order to see why this is true, consider an example.
Suppose the owner of a spreadsheet enters a value of 135 Mexican pesos. Suppose the spreadsheet is transformed into a data warehouse, but the data warehouse keeps track of money in US dollars. As the data from the spreadsheet is written into the data warehouse, the transformation...