sudo -u postgres psql
postgres=# create database mydb;
postgres=# create user myuser with encrypted password 'mypass';
postgres=# grant all privileges on database mydb to myuser;su - postgres
# if not created
createuser test
# now create db
createdb testdb
alter user testuser with encrypted password 'qwerty';
grant all privileges on database testdb to testuser;susudo -u postgres
psqlpostgres=# create database mydb;
postgres=# create user myuser with encrypted password 'mypass';
postgres=# grant all privileges on database mydb to myuser;