Работает следующее
select public.hstore('new_users', 'a');
Но это не работает
select public.hstore('new_users', 'a') || public.hstore('a', 'a');
Ошибка
SQL Error [42883]: ERROR: operator does not exist: public.hstore || public.hstore
Hint: No operator matches the given name and argument type(s). You might need to add explicit type casts.
Position: 40
org.postgresql.util.PSQLException: ERROR: operator does not exist: public.hstore || public.hstore
Hint: No operator matches the given name and argument type(s). You might need to add explicit type casts.
Position: 40