select name,
count(case when value <= 5 then 1 end) as "0-5",
count(case when value > 5 and value <= 10 then 1 end) as "5-10",
count(case when value > 10 and value <= 15 then 1 end) as "10-15"
from the_table
group by name;
Com a próxima versão 9.4, isso pode ser escrito um pouco mais legível:
select name,
count(*) filter (where amount <= 5) as "0-5",
count(*) filter (where value > 5 and value <= 10) as "5-10",
count(*) filter (where value > 10 and value <= 15) as "10-15"
from the_table
group by name;