This qualifies as a minor annoyance because there is an easy workaround. If you have been using other databases, though, it will probably catch you out the first time, and when you forget.
select
postal_code,
count(*)
from
customer
group by
postal_code
order by
count(*);
This syntax works in most databases, but with Hive you get this error:
Error: Error while compiling statement: FAILED: SemanticException [Error 10128]: Line 9:4 Not yet supported place for UDAF 'count' (state=42000,code=10128)
(UDAF stands for "User-Defined Aggregation Function" apparently - but count() isn't user-defined.)
The workaround is to give the count(*) an alias, like this:
select
postal_code,
count(*) as frequency
from
customer
group by
postal_code
order by
frequency;
Then it works fine. Every little hinders.
This issue is related to Hive, By Default, Does Not Allow Order By Result Column Number