Postgres: select the sum of values and then sum this again

Question

I tried a lot but can´t find the right way. If I select values in Postgres and sum them it looks like this:

SELECT name,sum(size) as total
FROM mytable group         


        

Answer 1

Well this should help you:

select sum(innerselect.innertotal) as outertotal from 
    (select sum(size) as innertotal from mytable group by name) as innerselect