DROP TABLE IF EXISTS t1;
create table t1 (a int key, b int) engine ndb;
create table t2 (a int key, b int) engine ndb;
insert into t1 values (0,0),(1,1),(2,2);
insert into t2 select * from t1;
begin;
set transaction_allow_batching=1;
update t1 set b=0 where a=2;
commit;
@ndb_execute_count:=VARIABLE_VALUE-@ndb_init_execute_count
1
select * from t1 order by a;
a	b
0	0
1	1
2	0

With batching only 1 roundtrip

begin;
set transaction_allow_batching=1;
insert into t1 values (10,10);
insert into t2 values (10,10);
commit;
@ndb_execute_count:=VARIABLE_VALUE-@ndb_init_execute_count
1
select * from t1 order by a;
a	b
0	0
1	1
2	0
10	10

Without batching only 3 roundtrips

begin;
set transaction_allow_batching=0;
insert into t1 values (11,11);
insert into t2 values (11,11);
commit;
@ndb_execute_count:=VARIABLE_VALUE-@ndb_init_execute_count
3
select * from t1 order by a;
a	b
0	0
1	1
2	0
10	10
11	11
drop table t1, t2;