Question 44: Which query belongs to the execution plan?

Check the scenario below:

create table egen
  select 1 as n union select 2 union select 3 union
  select 4 union select 5 union select 6 union
  select 7 union select 8 union select 9 union select 10;

create table e1tst
  select floor(rand()*10) + 1 as etype,
  adddate('2010-01-01', interval rand()*360 day) as edate,
  (rand()*1000000/100) as esum
  from egen a,egen b,egen c,egen d,egen e;

create table e2tst select n etype,uuid() as ename from egen a;

alter table e1tst add index (edate,etype);
alter table e2tst add index (etype);

+--+------------------+---+-----+--------+-----+-------+----+----+-----------+
|id|select_type       |tab|type |possible|key  |key_len|ref |rows|Extra      |
+--+------------------+---+-----+--------+-----+-------+----+----+-----------+
| 1|PRIMARY           | v1|range| edate  |edate|  9    |NULL|2426|Using where|
| 2|DEPENDENT SUBQUERY| v2|ref  | etype  |etype|  8    |func|   2|Using where|
+--+------------------+---+-----+--------+-----+-------+----+----+-----------+
2 rows in set (0.00 sec)

Which query belongs to the execution plan?

a) select edate,ename,sum(esum) from e1tst v1
    inner join e2tst v2 on (v1.etype=v2.etype)
    where edate between '2010-01-01' and '2010-01-10'
    group by edate,ename;

b) select edate,
    (select v2.ename from e2tst v2 where v1.etype=v2.etype)
    as ename,sum(esum)
    from e1tst v1
    where edate between '2010-01-01' and '2010-01-10'
    group by edate,etype;

c) select s1.edate,s2.ename,s1.sumesum
    from (select edate,etype,sum(esum) as sumesum
            from e1tst v1
            where edate between '2010-01-01' and '2010-01-10'
            group by edate,etype) s1
    inner join e2tst s2 on (s1.etype=s2.etype);

 
[ Basic Optimizations (10%) - Using Indexes for Optimization ]