Make it possible to use custom SQL in Tableau without being punished by sub-optimal performance.
Normal usage for me - and I believe for most who know how to write a query in SQL - is to write the query in a query tool until it is correct and performs well. Not before this is done is it added to Tableau. The simple solution is to paste it into Tableau as Custom SQL, but it often comes at the price of poor performance.
Therefore the recommended practice is to use Tableau's join dialog.
The sad thing is that this is:
- Difficult to reuse
I do understand this is aand therefore don't expect it to be implemented, at least not in near future. However, I think it is important with more awareness of the issue, because it might lead to this or other improvements that limit costly time-wasting in reusing proven queries.