1 -You can create truly temporary tables by using "#" as the first character of the table name:
create table #temptable (...)
or:
select select_list
into #temptable ...
Temporary tables:
Exist only for the duration of the user session or for the scope of the procedure that creates them
Cannot be shared between user connections
Are automatically dropped at the end of the session or procedure (or can be dropped manually)


2 - You can create regular user tables in tempdb by specifying the database name in the command that creates the table:
create table tempdb..temptable (...)
or:
select select_list into tempdb..temptable
Regular user tables in tempdb:
Can persist across sessions
Can be used by bulk copy operations
Can be shared by granting permissions on them
Must be explicitly dropped by the owner (otherwise, they are removed when Adaptive Server is restarted)

3 -Worktables
Worktables are automatically created in tempdb by Adaptive Server for merge joins, sorts, and other internal server processes.


Скорее всего вы имеете ввиду пункт 2?

Он имеет смысл и в случае псевдовременной таблицы в нормальной базе данных.
Надо только спросить у автора вопроса : Временно-постоянная таблица и псевдовременная - это одно и тоже ?