Function SplitTupleTableSlot

src/backend/executor/nodeSplitUpdate.c:72–164

Split TupleTableSlot into a DELETE and INSERT TupleTableSlot */

/* Split TupleTableSlot into a DELETE and INSERT TupleTableSlot */
static void
SplitTupleTableSlot(TupleTableSlot *slot,
					List *targetList, SplitUpdate *plannode, SplitUpdateState *node,
					Datum *values, bool *nulls)
{
	ListCell *element;
	ListCell *deleteAtt = list_head(plannode->deleteColIdx);
	ListCell *insertAtt = list_head(plannode->insertColIdx);

	slot_getallattrs(slot);
	Datum	   *delete_values = node->deleteTuple->tts_values;
	bool	   *delete_nulls = node->deleteTuple->tts_isnull;
	Datum	   *insert_values = node->insertTuple->tts_values;
	bool	   *insert_nulls = node->insertTuple->tts_isnull;

	/* Iterate through new TargetList and match old and new values. The action is also added in this containsTuple. */
	foreach (element, targetList)
	{
		TargetEntry *tle = lfirst(element);
		AttrNumber attno = tle->resno;

		if (IsA(tle->expr, DMLActionExpr))
		{
			/* Set the corresponding action to the new tuples. */
			delete_values[attno - 1] = Int32GetDatum((int)DML_DELETE);
			delete_nulls[attno - 1] = false;

			insert_values[attno - 1] = Int32GetDatum((int)DML_INSERT);
			insert_nulls[attno -1 ] = false;
		}
		else if (attno <= list_length(plannode->insertColIdx))
		{
			/* Old and new values */
			int			deleteAttNo = lfirst_int(deleteAtt);
			int			insertAttNo = lfirst_int(insertAtt);

			if (deleteAttNo == -1)
			{
				delete_values[attno - 1] = (Datum) 0;
				delete_nulls[attno - 1] = true;
			}
			else
			{
				delete_values[attno - 1] = values[deleteAttNo - 1];
				delete_nulls[attno - 1] = nulls[deleteAttNo - 1];
			}

			insert_values[attno - 1] = values[insertAttNo - 1];
			insert_nulls[attno - 1] = nulls[insertAttNo - 1];

			deleteAtt = lnext(plannode->deleteColIdx, deleteAtt);
			insertAtt = lnext(plannode->insertColIdx, insertAtt);
		}
		else if (attno == node->output_segid_attno)
		{
			Assert(!nulls[node->input_segid_attno - 1]);

			delete_values[attno - 1] = values[node->input_segid_attno - 1];