GRANT ALL PRIVILEGES ON DATABASE db_name TO username;
select * from information_schema.role_table_grants where grantee='<user>';
grant select, insert, <other_permissions> on <table> to <role>;
sudo -u postgres
psqlpostgres=# create database mydb;
postgres=# create user myuser with encrypted password 'mypass';
postgres=# grant all privileges on database mydb to myuser;