EXPLAIN+ORDER BY: Different plans produced by SHOW EXPLAIN and EXPLAIN

SELECT al1.a FROM t1 AS al1, t1 AS al2 

WHERE al1.a = al2.a HAVING al1.a != 3 ORDER BY al1.a;

revision-id: psergey@askmonty.org-20120607171922-w5d79pe7733jrh2r

date: 2012-06-07 21:19:22 +0400

revno: 3412

id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	al1	index	a	a	4	NULL	98	Using where; Using index

1	SIMPLE	al2	ref	a	a	4	test.al1.a	11	Using index

id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra

1	SIMPLE	al1	index	a	a	4	NULL	8	Using index

1	SIMPLE	al2	ref	a	a	4	test.al1.a	11	Using index

CREATE TABLE t1 (a INT NOT NULL, KEY(a)) ENGINE=Aria;

INSERT INTO t1 VALUES (4),(8),(0),(0),(0),(7),(7),(5),

(3),(188),(4),(9),(6),(1),(5),(6),(2),(4),(231),(4),

(3),(3),(7),(6),(7),(9),(4),(4),(2),(1),(2),(194),(2),

(3),(8),(4),(9),(4),(5),(5),(9),(3),(8),(0),(98),(3),

(1),(0),(189),(8),(3),(3),(9),(6),(8),(3),(9),(5),(9),

(2),(2),(5),(8),(6),(9),(0),(3),(6),(5),(8),(2),(120),

(25),(1),(3),(1),(3),(153),(5),(9),(1),(8),(7),(6),(2),

(4),(7),(3),(8),(4),(6),(1),(7),(1),(7),(2),(1),(5);

--connect (con1,localhost,root,,)

let $con_id = `SELECT CONNECTION_ID()`;

EXPLAIN

SELECT al1.a FROM t1 AS al1, t1 AS al2

WHERE al1.a = al2.a HAVING al1.a != 3 ORDER BY al1.a;

--send

SELECT al1.a FROM t1 AS al1, t1 AS al2

WHERE al1.a = al2.a HAVING al1.a != 3 ORDER BY al1.a;

--connection default

let $fail = 100;

while ($fail)

{

  --error 0,ER_ERROR_WHEN_EXECUTING_COMMAND

  --eval SHOW EXPLAIN FOR $con_id

  --dec $fail

  if (!$mysql_errno)

  {

    let $fail = 0;

  }

}

let $pass = 5;

while ($pass)

{

  --error 0,ER_ERROR_WHEN_EXECUTING_COMMAND

  --eval SHOW EXPLAIN FOR $con_id

  --dec $pass

  if ($mysql_errno)

  {

    let $pass = 0;

  }

}

--connection con1

--disable_result_log

--reap