Any Transact-SQL command that requires data row sorting can benefit from parallel sorting techniques. These commands are:
create index commands and the alter table...add constraint commands that build indexes, unique and primary key
Queries that use the order by clause
Queries that use distinct
Queries that perform merge joins requiring sorts
Queries that use union (except union all)
Queries that use the reformatting strategy
In addition, any cursors that use the above commands can benefit from parallel sorting.