Function release_partition

src/backend/executor/nodeWindowAgg.c:1573–1605

* release_partition * clear information kept within a partition, including * tuplestore and aggregate results. */

 * tuplestore and aggregate results.
 */
static void
release_partition(WindowAggState *winstate)
{
	int			i;

	for (i = 0; i < winstate->numfuncs; i++)
	{
		WindowStatePerFunc perfuncstate = &(winstate->perfunc[i]);

		/* Release any partition-local state of this window function */
		if (perfuncstate->winobj)
			perfuncstate->winobj->localmem = NULL;
	}

	/*
	 * Release all partition-local memory (in particular, any partition-local
	 * state that we might have trashed our pointers to in the above loop, and
	 * any aggregate temp data).  We don't rely on retail pfree because some
	 * aggregates might have allocated data we don't have direct pointers to.
	 */
	MemoryContextResetAndDeleteChildren(winstate->partcontext);
	MemoryContextResetAndDeleteChildren(winstate->aggcontext);
	for (i = 0; i < winstate->numaggs; i++)
	{
		if (winstate->peragg[i].aggcontext != winstate->aggcontext)
			MemoryContextResetAndDeleteChildren(winstate->peragg[i].aggcontext);
	}

	if (winstate->buffer)
		tuplestore_end(winstate->buffer);
	winstate->buffer = NULL;
	winstate->partition_spooled = false;
}

/*
 * row_is_in_frame