Is Union Function work while creating Roles

[SumayyaSayyad4]

We have 200+ client role, where we want to union two table while specifying the filter is , Union, calculate, Evaluate, Filter is work while applying the static RLS

[SumayyaSayyad4]

@rubayatyasmin hey, I'm using import mode, i want to join two table in manage role dax expression box,

Creating 200+ roles and having each role Union and multiple filter is impact my performance in reporting?

[rubayatyasmin]

Even though you use import, UNION won't support RLS. The documentation is referring so. If you read it you will see it. 

As far performance, if your RLS is a  complicated and effects more DAX measures then it can lead to performance issue. Also, look for data model performance. It will also depend on the number of users. If your data model is not slow then performance should not be that bad. But tile refresh will take time. 

Here is a documentation to better understand RLS on performance impact. 

If my assistance helped you in any way, hit 👍. 

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Thanks

[rubayatyasmin · Accepted solution]

HI, @SumayyaSayyad4 

if my solution helps you in any way, hit 👍. and accept it as a solution. 

[rubayatyasmin]

HI, @SumayyaSayyad4 

Are you using Direct Query? If so then Union Function will not work. See the remarks here.

https://learn.microsoft.com/en-us/dax/union-function-dax

Note:  UNION function can be used to create new tables from existing ones, but if RLS is to be applied, it should be defined separately. Other DAX functions like CALCULATE and EVALUATE will respect RLS. As for roles, they define the rules of RLS. You can create roles and define what each role can see in terms of tables, columns, and rows.