OBIEE Physical Layer Complex Join Color? (Easy question!)

Question

This is a very silly question, but I just want to make sure.

I noticed the RPD I am working on right now, in the physical layer, there is a complex join between two tables.

The RPD works fine, but I was just curious I noticed that the diagram for the physical layer, the complex join is a red line between the two tables.

Are complex joins always shown as a RED line?

I rarely see physical joins in the physical layer, so just curious if the red line means an issue (red is usually an issue in my head) or is it just red because of a visual cues it's a complex join

[Deleted User] · Answer

Not really. If possible this should be enforced as much as possible. Complex joins with - sometimes really bizarre - conditions are a death sentence for the optimizer. Mostly it just forces full table scans on both sides of the join. Joy!

Robert Angel · Answer

As to is red a problem, I would say 'no' for non-data warehouse sources where life is rarely simple, but 'yes' (or at least it is a warning that it is suboptimal) for data warehouse sources, where the most performant join is always a single key to key join, but others may disagree with me on this...

Gianni Ceresa · Answer

Yes, red for complex joins, standard default thing.

And not just the color: a complex join also doesn't have the arrow, which a normal join (physical foreign key) has.