title: implementation of two semantic query optimization techniques in db2 universal database. authors: q cheng , j gryz , f koo , t leung , l liu , x qian , k schiefer. venue: vldb. year: 1999
title: implementation of two semantic query optimization techniques in db2 universal databaseâ '' , atkinson. authors: q cheng , j gryz , f koo , tyc leung , l liu , x qian ,. venue: international conference on very large data bases ( vldbâ ?? 99. year: nan