how does section access and Direct discovery work, I read that it was not possible with the section access implemented on desktop?how can I link a direct discovery to a datamodel (is it possible with autonumberhash functions)
The lack of client side "section access AND data reduction" is what is not supported. Not as you mentioned client side section access as a whole. Have a look at the document Direct Discovery Technical Addendum_11.2_SR11_and_Sense.pdf on page 19 you will find the bullet list with this limitation mentioned:
Client side section access and data reduction
In my interpretation of what Qlik means it does not exclude using section access on client side - but you will not get data reduction. That might or might not be a limitation you could live with - but it doesn't prevent you in connecting Direct Discovery data with your data model as such.
So let's say that I have this attached data model.
The UserAccess table is a section access table and DD is a direct discovery table. Will this work? After reload I get it to reduce as expected but when I close and reopen the document the direct discovery dimension data is gone. The measure or detail fields is still there...
It would be interesting to see if SOMEONE can create an application with section access and DD In the most simplest form.. I have NO success whatsoever on this.