set storage_engine='tokudb';
drop table if exists t;
create table t (a int primary key, b int);
insert into t values (1,0),(2,1),(3,0);
begin;
update t set b=b+1 where b>0;
set transaction isolation level serializable;
select * from t where a!=2;
commit;
a	b
1	0
3	0
drop table t;