create or replace function create_test_hash() returns bool as $$
declare
	coll bigint default 500;
	-- tweak this to where create index gets really slow
	max_coll bigint default 50000000;
begin
	loop
		raise notice 'staring %', coll; execute 'create table test_hash_'|| coll ||'(num int8);';
		execute 'insert into test_hash_'|| coll ||' (num) select n from generate_series(0, '|| max_coll ||') as n;';
		execute 'insert into test_hash_'|| coll ||' (num) select (n+4294967296) * '|| max_coll ||'/'|| coll ||'::int from generate_series(0, '|| coll ||') as n;';
		coll := coll * 2;
		exit when coll >= max_coll;
	end loop;
	return true;
end
$$ language 'plpgsql';