what permissions are needed to select postgresql code example

Example 1: list all permissions on a table in postgres

SELECT grantee, privilege_type 
FROM information_schema.role_table_grants 
WHERE table_name='mytable'

Example 2: postgresql user permissions to database

sudo -u postgres 
psqlpostgres=# create database mydb;
postgres=# create user myuser with encrypted password 'mypass';
postgres=# grant all privileges on database mydb to myuser;