Forum Discussion

Impactful Individual

8 years ago

Union and Merging Slowing Performance Terribly

Hello All, I have a report which is using 20 SQL views and I am doing few transformations on each, then disabling their load and then creating a UNION of all 20 (the business need is in such a wa...

Impactful Individual

8 years ago

I am using import mode for each of the 20
Views, no direct query for now.

Solution Sage

8 years ago

Did you try not doing UNION and creating relation between tables on PowerBI ?

Else, are you using every column on your 20 tables ? I had the same issue, and creating view of my table with only the needed columns and keeping data only after 2013 solved my problem

nirvana_moksh
Impactful Individual
8 years ago
While troubleshooting this issue I did delete the UNION and the load was really quick but the UNION is definitely the issue, and I do need the UNION more so for making life easier when I do the row level security. Also, after this UNION process I merge it’s data with the Power Apps data as well in this model. So having the UNION is needed regardless.
- quentin_vigne
  Solution Sage
  8 years ago
  Maybe you could try to import the views without union and do the relationship between table on powerbi.
  
  You will do the RLS after that and it will still work
  
  We don't know what your data looks like so advising can be difficult
- Stachu
  Community Champion
  8 years ago
  could it be that the union is actually fast, but the merge with PowerApps data that you mentioned makes the whole process slow?
  have you tried loading just the union data (withouth merge) to the model? if so, how fast is it?
  - nirvana_moksh
    Impactful Individual
    8 years ago
    I have actually removed the Power Apps data and just kept the UNION but it still takes long. I am going to redo a few things today and see where it takes me.