in 'normal' sql queries, I can use an aggregate function with * to select all columns:

select sum(a+b), * from my_table

pinot query browser gives an error when I try this -- is there another way without specifically listing all the columns?

Currently pinot doesn't support mixing wildcard with other columns. Can you please create a github issue for this?

this is not a valid sql though, unless you group by all the columns(*)

Yes,

select a + b, * from myTable

is valid