An apparatus, computer-readable medium, and computer-implemented method for efficiently performing operations on distinct data values, including receiving a query directed to a column of data, the query defining one or more group sets for grouping the data retrieved in response to the query, and for each of the one or more group sets, generating one or more entity map vectors, the length of each entity map vector being equal to the number of unique data values in a domain which corresponds to the column of data, the position of each bit in the entity map vector corresponding to the lexical position of a corresponding unique data value in a lexically ordered list of the unique data values, and the value of each bit in the entity map vector indicating the presence or absence of the corresponding unique data value in the group set.