title: join synopses for approximate query answering. authors: swarup acharya , viswanath poosala , phillip b. gibbons , sridhar ramaswamy. venue: sigmod conference. year: 1999
title: icicles : self-tuning samples for approximate query answering. authors: venkatesh ganti , mong-li lee , raghu ramakrishnan. venue: very large data bases. year: 2000