I've run across a bug with order by:
select 1 as a order by a; -- works
select 1 as a, 2 as b order by a; -- works
select 1 as a, 2 as b order by a + b; ERROR: column "a" does not exist
select * from (select 1 as a, 2 as b) stuff order by a + b; -- works
---------------------------(end of broadcast)--------------------------- TIP 7: don't forget to increase your free space map settings
