Why does bi-directional makes dax query performance slow

Question

I have a set of tables (a,b,c,d), which have the following relation. Please note that this is not my own design.

A->B

C->B

B-->D Bi-directional

When I run a dax query with just down a sum(x), with the Bi-Directional turn-on, the query runs in 12 seconds and creates 67 queries.

When I run the same dax query with Many-One relation (turn off bi-directional), the query runs in 1.7 seconds and it create 12 queries only.

Any ideas.

amitchandak · Answer

Bi-direction relation, allows you to filter on both sides and it means you will lot more stuff to filter in.

Refer

Forum Discussion