create table t1(key1 char,v1 int);

create table t2(key2 char,v2 int);

insert into t1 values('a',1),('a',2),('b',3),('c',4),('a',13);
                        
insert into t2 values('b',10),('b',11),('a',12),('a',13),('e',14);
                         
select * from t1;-- 5
select * from t2;-- 5