▁by ▁Jud y ▁arrays ▁is ▁nearly ▁proportional ▁to ▁the ▁number ▁of ▁elements ▁in ▁the ▁Jud y ▁array . ▁ ▁Speed ▁Jud y ▁arrays ▁are ▁designed ▁to ▁minim ize ▁the ▁number ▁of ▁expensive ▁cache - line ▁fills ▁from ▁RAM , ▁and ▁so ▁the ▁algorithm ▁contains ▁much ▁complex ▁logic ▁to ▁avoid ▁cache ▁miss es ▁as ▁often ▁as ▁possible . ▁Due ▁to ▁these ▁cache ▁optim izations , ▁Jud y ▁arrays ▁are ▁fast , ▁especially ▁for ▁very ▁large ▁datasets . ▁On ▁data ▁sets ▁that ▁are ▁sequ ential ▁or ▁nearly ▁sequ ential , ▁Jud y ▁arrays ▁can ▁even ▁out perform ▁hash ▁tables , ▁since , ▁unlike ▁hash ▁tables , ▁the ▁internal ▁tree ▁structure ▁of ▁Jud y ▁arrays ▁maintain s ▁the ▁ordering ▁of ▁the ▁keys . ▁ ▁Draw back s ▁Jud y ▁arrays ▁are ▁extremely ▁complicated . ▁The ▁smallest ▁implementations ▁are ▁thousands ▁of ▁lines ▁of ▁code . ▁In ▁addition , ▁Jud y ▁arrays ▁are ▁optimized ▁for ▁machines ▁with ▁ 6 4 ▁byte ▁cache ▁lines , ▁making ▁them ▁essentially ▁un port able ▁without ▁a ▁significant ▁rewrite . ▁In ▁most ▁applications ▁the ▁possible ▁performance ▁advantage ▁is ▁too ▁small ▁to ▁justify ▁the ▁high ▁complexity ▁of ▁the ▁data ▁structure ▁implementation . ▁ ▁See ▁also ▁▁▁ ▁Rad ix ▁tree ▁ ▁Hash ▁array ▁mapped ▁tr ie ▁ ▁References ▁ ▁External ▁links ▁Main ▁Jud y ▁arrays ▁site ▁How ▁Jud y ▁arrays ▁work ▁and ▁why ▁they ▁are ▁so ▁fast ▁A ▁complete ▁technical ▁description ▁of ▁Jud y ▁arrays ▁An ▁independent ▁performance ▁comparison ▁of ▁Jud y ▁to ▁Hash ▁T ables ▁A ▁compact ▁implementation ▁of ▁Jud y ▁arrays ▁in ▁