Function select_current_set

src/backend/executor/nodeAgg.c:491–504

* Select the current grouping set; affects current_set and * curaggcontext. */

 * curaggcontext.
 */
static void
select_current_set(AggState *aggstate, int setno, bool is_hash)
{
	/*
	 * When changing this, also adapt ExecAggPlainTransByVal() and
	 * ExecAggPlainTransByRef().
	 */
	if (is_hash)
		aggstate->curaggcontext = aggstate->hashcontext;
	else
		aggstate->curaggcontext = aggstate->aggcontexts[setno];

	aggstate->current_set = setno;
}

/*
 * Switch to phase "newphase", which must either be 0 or 1 (to reset) or