title: selectivity estimation in spatial databases viswanath poosala , sridhar ramaswamy , swarup acharya sigmod conference 1999. authors: nan. venue: nan. year: nan
title: effective timestamping in databases kristian torp , christian s. jensen , richard thomas snodgrass 2000. authors: nan. venue: the vldb journal -- the international journal on very large data bases. year: nan