SQL query speed with two inner joins and concat?

I don't think you need to use an extra subselect statement. I took your faster statement and removed the inner select statement. Not sure how much this would affect execution time, but its a little bit cleaner, imho.

Eventually, I solved this problem by restructuring my database scheme.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.