/*
 * ExecAgg for hashed case: retrieving groups from hash table
 *
 * After exhausting in-memory tuples, also try refilling the hash table using
 * previously-spilled tuples. Only returns NULL after all in-memory and
 * spilled tuples are exhausted.
 */
static TupleTableSlot *
agg_retrieve_hash_table(AggState *aggstate)
{
	TupleTableSlot *result = NULL;

	while (result == NULL)
	{
		result = agg_retrieve_hash_table_in_memory(aggstate);
		if (result == NULL)
		{
			if (!agg_refill_hash_table(aggstate))
			{
				aggstate->agg_done = true;
				break;
			}
		}
	}

	return result;
}