title: implementation of two semantic query optimization techniques in db2 universal database. authors: k. bernhard schiefer , fred koo , t. y. cliff leung , linqi liu , jarek gryz , xiaoyan qian , qi cheng. venue: vldb. year: 1999
title: implementation of two semantic query optimization techniques in db2 universal database. authors: qi cheng , jarek gryz , fred koo , t. y. cliff leung , linqi liu , xiaoyan qian , k. bernhard schiefer. venue: very large data bases. year: 1999