Path Summaries and Path Partitioning in Modern XML Databases
  We study the applicability of XML path summaries in the context of current-day XML databases. We find that summaries provide an excellent basis for optimizing data access methods, which furthermore mixes very well with path-partitioned stores. We provide practical algorithms for building and exploiting summaries, and prove its benefits through extensive experiments. 
Andrei Arion (INRIA Futurs), Angela Bonifati, Ioana Manolescu (INRIA   Futurs), Andrea Pugliese