question: private static boolean shouldMaterializerInCurrentBlock ( double probabilityBlock , double probabilityChildren , int numMat ) { return probabilityBlock * Math . pow ( 0.9 , numMat - 1 ) < probabilityChildren ; }
target:  This is the cost function that decides whether a materialization should be inserted in the current block. <p> Note that this function does not take into account if a materialization is required despite the probabilities (e.g. there are usages in the current block).