  We revisit the random $m$-ary search tree and study a finer profile of its
node outdegrees with the purpose of exploring possibilities of data structure
compression. The analysis is done via P\'olya urns. The analysis shows that the
number of nodes of each individual node outdegree has a phase transition: Up to
$m=26$, the number of nodes of outdegree $k$, for $k=0,1, \ldots, m$, is
asymptotically normal; that behavior changes at $m = 27$. Based on the
analysis, we propose a compact $m$-ary tree that offers significant space
saving.
