Look if any column contains such a value

look_for_value.sql

create function pg_temp.look_for_value(value text) returns
  table(table_fullname text, column_name text)
  language plpgsql as $$
declare
  r record;
  found bool;
begin
  for r in select * from information_schema.columns
  loop
    table_fullname = format('%I.%I.%I', r.table_catalog, r.table_schema, r.table_name);
    column_name = r.column_name;
    execute format('select true from %s where %I::text = %L limit 1',
        table_fullname, column_name, value) into found;
    if found then return next; 
    end if;
  end loop;
end
$$;