title: heterogeneous database query optimization in db2 universal datajoiner shivakumar venkataraman , tian zhang vldb 1998. authors: nan. venue: nan. year: nan
title: implementation of two semantic query optimization techniques in db2 universal database qi cheng , jarek gryz , fred koo , t. y. cliff leung , linqi liu , xiaoyan qian , k. bernhard schiefer very large data bases 1999. authors: nan. venue: nan. year: nan