If you’ve installed postgresql on Ubuntu and it just doesn’t run and /etc/init.d/postgresql-8.3 start returns just a prompt with no error or any messages you’ve most likely encountered the same problem I had.
It seems that when you distupgrade Ubuntu to 8.04 and try to install postgresql configuration files for the default cluster are not created if you do apt-get install postgresql.
However everything is configured correctly when installing it with apt-get install postgresql-8.3.
You may need to create /etc/postgresql/8.3 directory yourself before trying to run apt-get especially if this isn’t your first attempt to (re)install postgres.
Try following steps:
dpkg -P postgresql postgresql-8.3 postgresql-client-8.3
apt-get install postgresql-8.3