or keep both adjency list and closure table: https://gist.github.com/desfrenes/733a83ef82b03ee701caa761951767c9 https://gist.github.com/desfrenes/733a83ef82b03e

or keep both adjency list and closure table: https://gist.github.com/desfrenes/733a83ef82b03ee701caa761951767c9 https://gist.github.com/desfrenes/733a83ef82b03ee701caa76195...