This is a general question which aim is to allow me to start digging on the subject by myself.
As I noticed the general opinion is that scene graphs are good for describing the scene in a level editor (or any editor that the game is using), but the game itself should use some sort of optimized data structure internally and the scene graphs should be somehow "translated" to that data structure before use.
What such internal data structures would be? How one would "translate" a scene graph to such structures.
In general - the more detail you can give me then better. Also references/links are more than welcome. :)