When a query references more than one dataset, InfoSum Platform accesses each dataset in turn, retrieving information and/or applying a filter. Each step of this process is known as a hop. The two datasets involved in a hop must be connected (meaning that you have permission to use both of them in queries), and they must share at least one common key.
For many queries, these rules will result in more than one possible path. InfoSum Platform will automatically choose the path likely to produce the best results, based on factors including the key fill rates. However, you may wish to override this choice based on your knowledge of the specific original data.