Better error when blank database

[dread]

When installing CKAN, when doing "paster serve development.ini", lots of users encounter the error for every request:

ProgrammingError: (ProgrammingError) relation "user" does not exist

This is because the database tables have not been created - they have forgotten or missed the "paster db init" step.

Can we provide a better error to say that the database is not initialised yet?

Implementation options

1. At the start of every request we reflect the database tables and check they are there. This is rather expensive!

2. Uncached requests to the home page start with a cheap database query. If there is an exception then return this error about database setup. I really like Drupal's page for this that has in large letters that the site is currently off-line. Below a line, in small letters, there are developer suggestions on what is wrong and where to look to fix it.