We have couple of dashboards that use Fact Table A and dimension tables D1, D2, D3 and D4. For this we created data extract TDE1.
Now we got another requirement that needs Fact Table A combined with Fact Table B (union all). And we need D1, D2, D3, D4 and 2 more dimension tables.
We can not use TDE1. We need to create another custom sql for extracting data for this new requirement and create TDE2.
We refresh the data every night, meaning we will pull data from common tables multiple times. With increase in data volume, the extracts take long time and could not be finished in 5-7 hours of window. (Incremental refresh can not be used due to updates on past data)
If Tableau supports a structure in which we can pull data from TDE 1, join with data from another extract or database table using proper join condition (not data blending), it would be great. Also pulling data from TDE is faster than pulling from DB.
Basically, the idea is pull data only once from each table. Then create a layer of many TDEs. Use dashboard specific TDEs to create a one TDE per dashboard.
I checked with Tableau people but this functionality is not supported.
Please let me know more inputs.