A method and system for estimating cardinalities for a plurality of
columns in a database system is disclosed. The method and system include
obtaining statistics collected for the plurality of columns. A first
portion of the statistics indicates at least one relationship between at
least a portion of the plurality of columns, while a second portion of
the statistics includes single column statistics. The method and system
also include utilizing the first portion and the second portion of the
statistics to estimate the cardinality for the plurality of columns.