teledb=# select count(1) from teledb_pg;
 count 
-------
     5
(1 row)

teledb=# select count(distinct id) from teledb_pg;
 count 
-------
     4
(1 row)

teledb=# select sum(id) from teledb_pg;
 sum 
-----
  11
(1 row)

teledb=# select max(id) from teledb_pg;
 max 
-----
   4
(1 row)

teledb=# select min(id) from teledb_pg;
 min 
-----
   1
(1 row)

teledb=# select avg(id) from teledb_pg;
        avg   
--------------------
 2.2000000000000000
(1 row)