[MonetDB-users] sql filter slow

Hi, Could you please help me with this query? I've got gender field in the table1 with values 'Female', 'Male', 'Unknown' sql1: select gender,count(*) from table1 group by gender returns results in 2 seconds sql2: select gender,count(*) from table where gender in ('Female','Male') group by gender returns results in 20 seconds Why the second query took longer when I'm selecting less values? Thanks. Dariusz.