have a table in vertica: test like this:
ID | name
1 | AA
2 | AB
2 | AC
3 | AD
3 | AE
3 | AF
The other method is to use GROUP_CONCAT from the strings package on github.
select id, group_concat(name) over (partition by id order by name) ag
from mytable
However there are some limitations with this method since analytical udx won't allow you to include other aggregates (and you'll have to inline it or use with to add more data to it).