no primary key

jharasym=# create table users (name varchar,age int);
CREATE TABLE
jharasym=# \d users
          Table "public.users"
 Column |       Type        | Modifiers
--------+-------------------+-----------
 name   | character varying |
 age    | integer           |

jharasym=# insert into users values ('Derecho', 25);
INSERT 0 1
jharasym=# insert into users values ('dijit', 27);
INSERT 0 1
jharasym=# select * from users;
  name   | age
---------+-----
 Derecho |  25
 dijit   |  27
(2 rows)

jharasym=#