Function notify_modified_relations_to_QD

src/backend/executor/nodeModifyTable.c:3807–3861

* notify_modified_relations_to_QD * Send modified relation info back to QD through extend libpq protocol. */

 * Send modified relation info back to QD through extend libpq protocol.
 */
static void
notify_modified_relations_to_QD(ModifyTableState *node)
{
	StringInfoData buf;
	HASH_SEQ_STATUS scan;
	ModifiedLeafRelidsData *r;
	List *inserted = NIL;
	List *updated = NIL;
	List *deleted = NIL;

	hash_seq_init(&scan, node->modified_leaf_relids);

	pq_beginmessage(&buf, PQExtendProtocol);

	while ((r = (ModifiedLeafRelidsData *) hash_seq_search(&scan)) != NULL)
	{
		switch (r->key.cmd)
		{
			case CMD_INSERT:
				inserted = lappend_oid(inserted, r->key.relid);
				break;
			case CMD_UPDATE:
				updated = lappend_oid(updated, r->key.relid);
				break;
			case CMD_DELETE:
				deleted = lappend_oid(deleted, r->key.relid);
				break;
			default:
				Assert(false);
				break;
		}
	}

	if (inserted != NIL)
	{
		send_subtag(&buf, EP_TAG_I, inserted);
		pfree(inserted);
	}

	if (updated != NIL)
	{
		send_subtag(&buf, EP_TAG_U, updated);
		pfree(updated);
	}

	if (deleted != NIL)
	{
		send_subtag(&buf, EP_TAG_D, deleted);
		pfree(deleted);
	}

	pq_sendint32(&buf, EP_TAG_MAX); /* Finish this run. */
	pq_endmessage(&buf);
	pq_flush(); /* Flush to notify QD in time. */
}

/*
 * send_subtag