MW-402 cascading FK issue (5.7 version)

Optimizing cascade node list traversal, which could turn out as
performance bottleneck
Even this current cascade node check could be skipped, but a dedicated
mtr test is needed to confirm that

Author: sjaakola

storage/innobase/row/row0upd.cc

@@ -2434,15 +2434,24 @@ row_upd_sec_index_entry(
 		row_ins_sec_index_entry() below */
 		if (!rec_get_deleted_flag(
 			    rec, dict_table_is_comp(index->table))) {
+
+#ifdef WITH_WSREP
+			que_node_t *parent = que_node_get_parent(node);
+#endif /* WITH_WSREP */
+
 			err = btr_cur_del_mark_set_sec_rec(
 				flags, btr_cur, TRUE, thr, &mtr);
+
 			if (err != DB_SUCCESS) {
 				break;
 			}
 #ifdef WITH_WSREP
-			if (!referenced && foreign
-			    && wsrep_must_process_fk(node, trx)
-			    && !wsrep_thd_is_BF(trx->mysql_thd, FALSE)) {
+			if (!referenced && foreign &&
+			    wsrep_on(trx->mysql_thd) &&
+			    !wsrep_thd_is_BF(trx->mysql_thd, FALSE) &&
+			    (!parent || (que_node_get_type(parent) !=
+			     QUE_NODE_UPDATE)                     ||
+			    ((upd_node_t*)parent)->cascade_upd_nodes->empty())) {
 				ulint*	offsets = rec_get_offsets(
 					rec, index, NULL, ULINT_UNDEFINED,
 					&heap);
@@ -2661,6 +2670,9 @@ row_upd_clust_rec_by_insert(
 	rec_t*		rec;
 	ulint*		offsets			= NULL;
 
+#ifdef WITH_WSREP
+	que_node_t *parent = que_node_get_parent(node);
+#endif /* WITH_WSREP */
 	ut_ad(node);
 	ut_ad(dict_index_is_clust(index));
 
@@ -2748,7 +2760,13 @@ row_upd_clust_rec_by_insert(
 				goto err_exit;
 			}
 #ifdef WITH_WSREP
-		} else if (foreign && wsrep_must_process_fk(node, trx)) {
+		} else if (foreign && wsrep_on(trx->mysql_thd) &&
+			 (!parent || (que_node_get_type(parent) != QUE_NODE_UPDATE) ||
+			 ((upd_node_t*)parent)->cascade_upd_nodes->empty())) {
+
+			err = wsrep_row_upd_check_foreign_constraints(
+				node, pcur, table, index, offsets, thr, mtr);
+
 			switch (err) {
 			case DB_SUCCESS:
 			case DB_NO_REFERENCED_ROW:
@@ -2956,10 +2974,15 @@ row_upd_del_mark_clust_rec(
 	dberr_t		err;
 	rec_t*		rec;
 	trx_t*		trx = thr_get_trx(thr);
+
 	ut_ad(node);
 	ut_ad(dict_index_is_clust(index));
 	ut_ad(node->is_delete);
 
+#ifdef WITH_WSREP
+	que_node_t *parent = que_node_get_parent(node);
+#endif /* WITH_WSREP */
+
 	pcur = node->pcur;
 	btr_cur = btr_pcur_get_btr_cur(pcur);
 
@@ -2985,9 +3008,13 @@ row_upd_del_mark_clust_rec(
 		err = row_upd_check_references_constraints(
 			node, pcur, index->table, index, offsets, thr, mtr);
 #ifdef WITH_WSREP
-	} else if (foreign && wsrep_must_process_fk(node, trx)) {
+	} else if (trx && wsrep_on(trx->mysql_thd)  &&
+	    (!parent || (que_node_get_type(parent) != QUE_NODE_UPDATE) ||
+	    ((upd_node_t*)parent)->cascade_upd_nodes->empty())) {
+
 		err = wsrep_row_upd_check_foreign_constraints(
 			node, pcur, index->table, index, offsets, thr, mtr);
+
 		switch (err) {
 		case DB_SUCCESS:
 		case DB_NO_REFERENCED_ROW: