Michael N. Gubanov Lucian Popa C. T. Howard Ho Hamid Pirahesh Jeng-Yih Chang Shr-Chang Chen 1598-1601 2009 2 PVLDB 2 http://www.vldb.org/pvldb/2/vldb09-1016.pdf db/journals/pvldb/pvldb2.html#GubanovPHPCC09