TOPN

[pstanek]

I try to create TOP 20, but I can´t find function RANKX.  I work in direct query. Is there possible to create top 20 in direct query?

[radpir · Accepted solution]

hi,

some of the functions are disabled by default in DirectQuery mode.

to enable them, you need to got to Options and Settings -> Options->Direct Query and then check the Allow unrestricted measures in DirectQuery mode option.

after that you need to restart powerbi and the rankx function should be available.

[pstanek]

I was always afraid of allowing that option because I don´t know what it will do about all function. I must be sure they will still calculate  correctly.

[radpir]

those functions should work correctly. they are disable for potential performance issues.

here what  Microsoft says about this:

'There are a set of DAX functions that have been disabled by default in DirectQuery mode. This is done in order to avoid performance issues with these functions when working in DirectQuery mode, as these calculations can get very expensive to run in the server.'