It is not uncommon to begin working on a dataset in Tableau (or anywhere else, for that matter), before realising halfway through your analysis that you are missing a field or calculation. If this is a data source you manipulated earlier in Alteryx, it’s normally a simple case of re-opening the workflow and making the necessary adjustments.
However, nothing in data prep is ever that easy, and one particular error may crop up. When you go to save the file (and therefore overwrite the previous file that you were using elsewhere), Alteryx will error: without closing the file everywhere else first, you will not be able to overwrite the file. This is problematic if you have already done a significant amount of analysis and do not want to lose your progress.
Luckily, I have the solution!
Imagine you are in Tableau, working on the data, and then you realise your mistake. Instead of caving and simply starting from scratch, try this.
First, delete the data source as you would normally in Tableau - yes, this will break your view (or even delete it), but don’t panic! Next, go back into Alteryx, make the necessary adjustments and save/overwrite your file. This will no longer error (unless the file is also open somewhere else), and will allow you to overwrite the file as intended.
This is normally where everything falls apart, but if you go back into Tableau, there is an insultingly easy workaround: just click undo. By selecting undo, you will bring the data source back into Tableau, albeit in its original state.
From here, you can simply select to update the data source, and suddenly your new changes will be implemented, without any loss to your visualisation inside Tableau!