text: --
  -- procedure
  --
  create or replace procedure {SCHEMA}number_urls (table_name character varying, url_column character varying, number_column character varying)
  as $$
  declare
      q character varying := 'insert into {SCHEMA}url_numbers (url) ';
  begin
  q := q || '(select url from (' ||
  '(select distinct ' || url_column || ' as url from {SCHEMA}' || table_name;
  if number_column is not null then
    q := q || ' where ' || number_column || ' = 0';
  end if;
  q := q || ') left join {SCHEMA}url_numbers using (url)) where number is null);';
  execute q;
  end;
  $$ language plpgsql;