title: vxmlr : a visual xml-relational database system aoying zhou , wenyun ji , shihui zheng , hongjun lu , yuqi liang , zengping tian , long zhang vldb 2001. authors: nan. venue: nan. year: nan
title: cost estimation of user-defined methods in object-relational database systems 1999. authors: jihad boulos , kinji ono. venue: acm sigmod record. year: nan