docs: def main_dump(paths, directory, dry_run):
      """dump all or part of the prom data, currently only works on Postgres databases
  
      basically just a wrapper around `dump backup` https://github.com/Jaymon/dump
      """
      table_map = get_table_map(paths)
  
      for conn_name, conn_info in table_map.items():
          inter = conn_info["interface"]
          conn = inter.connection_config
          table_names = conn_info["table_names"]
  
          cmd = get_base_cmd("backup", inter, directory)
          cmd.extend(table_names)
  
          if dry_run:
              echo.out(" ".join(cmd))
  
          else:
              run_cmd(cmd)