Filter generate is very slow in DirectQuery Mode

[mim]

I have two Tables, Budget (dimension Table) and Installed Quantity (Fact Tables), linked as multiple to Multiple.

Installed Quantity is DirectQuery as it change frequently

Budget is import as it change only once a month.

to calculate Value Achieved, I am using this measure

Value Achieved=
VAR _Table =
    FILTER (
        GENERATE ( Budget_Resources, Installed_Qty ),
        Budget_Resources[PK] = Installed_Qty[PK]
    )
RETURN
    SUMX ( _Table, [Resource Net amount/unit] * [Installed_Qty] )

when in import mode for both, it works fine, but when I changed Installed QTY to DirectQuery, it is become extremely slow, 2 minutes to render ? is there a better way 

[mim · Accepted solution]

I should have checked this previous answear before

https://community.powerbi.com/t5/Desktop/left-outer-join-using-dax-Multiple-to-Multiple/td-p/218906

[amitchandak]

@mim , are these tables not joined in the model on PK, what is the need for generating it in the measure?

If they are already joined on PK then avoid this GENERATE, if you need multiple column join use combinevalues

[mim]

@amitchandak  how to get a table, that containes two columns from two tables, they are linked on multiple to multiple, so I can't use related ?