a tree - structured database is collapsed into a two - column table . the two - column table includes a characteristic key value for a given leaf node in the first column and the system identification relating to the characteristic key value in the second column and also identifying the node that leads to the characteristic key value . data is presented by coupling the characteristic key value with a transaction table . a query that is formulated in an infocube may be translated to a relational data base query , collapsed , and reformulated into an infocube result set , or vice versa .