code: def export_db(filename=None, remote=False):
      
      local_machine()
      if not filename:
          filename = settings.DB_DUMP_FILENAME
      if remote:
          backup_dir = settings.FAB_SETTING('SERVER_DB_BACKUP_DIR')
      else:
          backup_dir = ''
  
      local('pg_dump -c -Fc -O -U {0}{1} {2} -f {3}{4}'.format(
          env.db_role, HOST, env.db_name, backup_dir, filename))
docs: Exports the database.
  
      Make sure that you have this in your ``~/.pgpass`` file:
  
      localhost:5433:*:<db_role>:<password>
  
      Also make sure that the file has ``chmod 0600 .pgpass``.
  
      Usage::
  
          fab export_db
          fab export_db:filename=foobar.dump