Use these commands to generate a self-signed SSL certificate (e.g. for Apache):

# openssl genrsa 1024 > server.key
# openssl req -new -key server.key -x509 -days 90 -out server.crt

Use the following query to show all tables without primary keys:

SELECT
  nspname AS schema,
  relname AS table
FROM pg_class
  LEFT JOIN pg_constraint ON
    pg_constraint.contype = 'p' AND
    conrelid = pg_class.oid
  JOIN pg_namespace ON
    pg_namespace.oid = pg_class.relnamespace
WHERE
  relkind = 'r' AND contype IS NULL;