Views, find content types with field NOT IN other content type Content Type A
-Nid A
-Field A

Content Type B
-Nid B
-Reference Nid A

How can I find in a view all As that have no reference in B ?

in sql this is

select A.field
FROM TABLE A
LEFT JOIN TABLE B
ON A.KEY = B.KEY 
WHERE B.key IS NULL


I have tried Views reference filter, but it is very slow and consume a lot of memory (the trick with this modules is not a join but a SELECT... NOT IN (...).

Which is very inefficient, because, i have 16.000 As and 14.000 Bs.

Is there any efficient solutions with views?

Thanks.
Well, maybe it is idiotic, but finally I understood the issue with the relationships and the "referenced vs referencing"

So, what I did was:

relationships : "Content referenCING Content from A_REFERENCE_IN_B"
Fields A (the fields you want)
Filter type = Type A
Filter NID (using the relationship) , is null.

Amazing, and super fast.

The important part is REFERENCING not referenced.

Thanks.