Comment 6 for bug 1000051

I cannot reproduce this bug on MySQL 5.6.6-m9 and MariaDB 5.5.23 because the test data here (https://bugs.launchpad.net/maria/+bug/1000051/+attachment/3148604/+files/A.data) and the test query does not seem to force MySQL/MariaDB to use ICP, even if I change the sort order to ASC.

MariaDB 5.5.23 EXPLAIN output:
MariaDB [test]> EXPLAIN SELECT SQL_NO_CACHE * FROM A, B WHERE b1 = a1 AND a3 = "3" ORDER BY a2 DESC\G
*************************** 1. row ***************************
           id: 1
  select_type: SIMPLE
        table: A
         type: ref
possible_keys: a3,a3_2
          key: a3_2
      key_len: 2
          ref: const
         rows: 731
        Extra: Using where
*************************** 2. row ***************************
           id: 1
  select_type: SIMPLE
        table: B
         type: eq_ref
possible_keys: PRIMARY
          key: PRIMARY
      key_len: 4
          ref: test.A.a1
         rows: 1
        Extra: Using index
2 rows in set (0.00 sec)

MariaDB [test]> EXPLAIN SELECT SQL_NO_CACHE * FROM A, B WHERE b1 = a1 AND a3 = "3" ORDER BY a2 ASC\G
*************************** 1. row ***************************
           id: 1
  select_type: SIMPLE
        table: A
         type: ref
possible_keys: a3,a3_2
          key: a3_2
      key_len: 2
          ref: const
         rows: 731
        Extra: Using where
*************************** 2. row ***************************
           id: 1
  select_type: SIMPLE
        table: B
         type: eq_ref
possible_keys: PRIMARY
          key: PRIMARY
      key_len: 4
          ref: test.A.a1
         rows: 1
        Extra: Using index
2 rows in set (0.00 sec)

MySQL 5.6.6-m9 EXPLAIN output:
mysql> EXPLAIN SELECT SQL_NO_CACHE * FROM A, B WHERE b1 = a1 AND a3 = "3" ORDER BY a2 DESC\G
*************************** 1. row ***************************
           id: 1
  select_type: SIMPLE
        table: A
         type: ref
possible_keys: a3,a3_2
          key: a3_2
      key_len: 2
          ref: const
         rows: 731
        Extra: Using where
*************************** 2. row ***************************
           id: 1
  select_type: SIMPLE
        table: B
         type: eq_ref
possible_keys: PRIMARY
          key: PRIMARY
      key_len: 4
          ref: test.A.a1
         rows: 1
        Extra: Using index
2 rows in set (0.00 sec)

mysql> EXPLAIN SELECT SQL_NO_CACHE * FROM A, B WHERE b1 = a1 AND a3 = "3" ORDER BY a2 ASC\G
*************************** 1. row ***************************
           id: 1
  select_type: SIMPLE
        table: A
         type: ref
possible_keys: a3,a3_2
          key: a3_2
      key_len: 2
          ref: const
         rows: 731
        Extra: Using where
*************************** 2. row ***************************
           id: 1
  select_type: SIMPLE
        table: B
         type: eq_ref
possible_keys: PRIMARY
          key: PRIMARY
      key_len: 4
          ref: test.A.a1
         rows: 1
        Extra: Using index
2 rows in set (0.00 sec)