Description:
 EXPLAIN returns invalid/wrong information for simple SELECT:

How to repeat:
create table t2 (a int, b int, c int, d int, primary key(a)) engine=Jstar;
insert into t2 values
(1,1,1,1),(2,2,2,2),(3,3,3,3),(4,4,4,4),(5,5,5,5),(6,6,6,6),(7,7,7,7),(8,8,8,8);
explain select distinct(a) from t2;

Output:
+----+-------------+-------+------+---------------+------+---------+------+------+--------
---------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+-------+------+---------------+------+---------+------+------+--------
---------+
| 1 | SIMPLE | t2 | ALL | NULL | NULL | NULL | NULL | 1000 | Using temporary |
+----+-------------+-------+------+---------------+------+---------+------+------+--------
---------+

Test case is falcon_bug_22144.test.

Calvin,  The EXPLAIN feature is not under the control of Falcon.