begin;

create or replace function swh_count_total_indexes_size()
  returns bigint
  language plpgsql
as $$
declare
    s bigint;
    l bigint;
    t text;
begin
    s := 0;

    for t in
        select distinct tablename from pg_tables where schemaname='public'
    loop
        select pg_indexes_size(t) into l;
        s := s + l;
    end loop;

    return s;
end
$$;

select pg_size_pretty(swh_count_total_indexes_size());

rollback;