two questions

I am having two questions about psql:

1. How to define a relation with an attribute which takes set values?
Not really sure what you mean....

eg. I would like to define a table like
create table emp (name text, tele Set(string)); -- it does
not work
One tuple may look like 'Jerry', {83023381,83023800}
I can not use array since an array is not a set.

2. How to populate instances to a table referring another table? An
example:
Create table CITIES (name text, population float);
Insert into cities values ('Adelaide', 100.0);
Create table people(name text, live_in CITIES);
How to insert a tuple into people saying that 'Jerry' lives in
Adelaide?
I can not use
INSERT INTO people('Jerry', 'Adelaide');
since live_in is not a string, it is a table named CITIES
I am trying to use object reference of OR. Thus a reference path
can be formed.

Jerry Liu, Australia