An option whether to rerun all previous steps would save time when nothing has changed from previous steps. Currently, if queries become complicated with multiple sources, it can take up to 5 minutes...
I agree that this is a big problem. I'm writing this now while the query refreshes. I have a single, small data source and a very long complex query, and have the same problem. The feature would particularly be good when creating new queries or adding steps to the end of the query as none of the previous data could have changed.
