Hi, I'm getting ICP with your test case (tried 5.5.27 which is the latest 5.5 release): MariaDB [test]> CREATE TABLE `icp_test` ( -> `i` int(11) NOT NULL, -> `k` int(11) NOT NULL, -> `v` char(32) DEFAULT NULL, -> KEY `k` (`k`,`i`) -> ) ENGINE=InnoDB DEFAULT CHARSET=latin1; Query OK, 0 rows affected (0.12 sec) MariaDB [test]> SOURCE icp_test.dump; Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.05 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.07 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 21539 rows affected (0.93 sec) Records: 21539 Duplicates: 0 Warnings: 0 Query OK, 21405 rows affected (0.89 sec) Records: 21405 Duplicates: 0 Warnings: 0 Query OK, 21405 rows affected (1.27 sec) Records: 21405 Duplicates: 0 Warnings: 0 Query OK, 21000 rows affected (0.91 sec) Records: 21000 Duplicates: 0 Warnings: 0 Query OK, 20977 rows affected (1.40 sec) Records: 20977 Duplicates: 0 Warnings: 0 Query OK, 20975 rows affected (1.22 sec) Records: 20975 Duplicates: 0 Warnings: 0 Query OK, 20976 rows affected (1.21 sec) Records: 20976 Duplicates: 0 Warnings: 0 Query OK, 20976 rows affected (0.94 sec) Records: 20976 Duplicates: 0 Warnings: 0 Query OK, 20974 rows affected (1.23 sec) Records: 20974 Duplicates: 0 Warnings: 0 Query OK, 20975 rows affected (1.89 sec) Records: 20975 Duplicates: 0 Warnings: 0 Query OK, 20975 rows affected (1.68 sec) Records: 20975 Duplicates: 0 Warnings: 0 Query OK, 20976 rows affected (1.22 sec) Records: 20976 Duplicates: 0 Warnings: 0 Query OK, 20977 rows affected (1.39 sec) Records: 20977 Duplicates: 0 Warnings: 0 Query OK, 20976 rows affected (1.54 sec) Records: 20976 Duplicates: 0 Warnings: 0 Query OK, 20977 rows affected (1.74 sec) Records: 20977 Duplicates: 0 Warnings: 0 Query OK, 20976 rows affected (0.99 sec) Records: 20976 Duplicates: 0 Warnings: 0 Query OK, 20977 rows affected (1.34 sec) Records: 20977 Duplicates: 0 Warnings: 0 Query OK, 20978 rows affected (1.99 sec) Records: 20978 Duplicates: 0 Warnings: 0 Query OK, 20975 rows affected (2.26 sec) Records: 20975 Duplicates: 0 Warnings: 0 Query OK, 20976 rows affected (1.35 sec) Records: 20976 Duplicates: 0 Warnings: 0 Query OK, 20975 rows affected (2.18 sec) Records: 20975 Duplicates: 0 Warnings: 0 Query OK, 20979 rows affected (1.67 sec) Records: 20979 Duplicates: 0 Warnings: 0 Query OK, 20976 rows affected (1.80 sec) Records: 20976 Duplicates: 0 Warnings: 0 Query OK, 20977 rows affected (1.27 sec) Records: 20977 Duplicates: 0 Warnings: 0 Query OK, 20976 rows affected (1.94 sec) Records: 20976 Duplicates: 0 Warnings: 0 Query OK, 20976 rows affected (2.09 sec) Records: 20976 Duplicates: 0 Warnings: 0 Query OK, 20976 rows affected (1.69 sec) Records: 20976 Duplicates: 0 Warnings: 0 Query OK, 20976 rows affected (1.63 sec) Records: 20976 Duplicates: 0 Warnings: 0 Query OK, 20975 rows affected (3.62 sec) Records: 20975 Duplicates: 0 Warnings: 0 Query OK, 20976 rows affected (1.31 sec) Records: 20976 Duplicates: 0 Warnings: 0 Query OK, 20974 rows affected (1.06 sec) Records: 20974 Duplicates: 0 Warnings: 0 Query OK, 20976 rows affected (2.50 sec) Records: 20976 Duplicates: 0 Warnings: 0 Query OK, 20975 rows affected (1.12 sec) Records: 20975 Duplicates: 0 Warnings: 0 Query OK, 20975 rows affected (1.06 sec) Records: 20975 Duplicates: 0 Warnings: 0 Query OK, 20976 rows affected (2.84 sec) Records: 20976 Duplicates: 0 Warnings: 0 Query OK, 20607 rows affected (1.52 sec) Records: 20607 Duplicates: 0 Warnings: 0 Query OK, 20565 rows affected (2.88 sec) Records: 20565 Duplicates: 0 Warnings: 0 Query OK, 20563 rows affected (2.95 sec) Records: 20563 Duplicates: 0 Warnings: 0 Query OK, 20563 rows affected (1.42 sec) Records: 20563 Duplicates: 0 Warnings: 0 Query OK, 20565 rows affected (3.37 sec) Records: 20565 Duplicates: 0 Warnings: 0 Query OK, 20563 rows affected (1.84 sec) Records: 20563 Duplicates: 0 Warnings: 0 Query OK, 20564 rows affected (4.93 sec) Records: 20564 Duplicates: 0 Warnings: 0 Query OK, 20562 rows affected (1.66 sec) Records: 20562 Duplicates: 0 Warnings: 0 Query OK, 20566 rows affected (1.69 sec) Records: 20566 Duplicates: 0 Warnings: 0 Query OK, 20564 rows affected (4.25 sec) Records: 20564 Duplicates: 0 Warnings: 0 Query OK, 20565 rows affected (1.89 sec) Records: 20565 Duplicates: 0 Warnings: 0 Query OK, 20564 rows affected (4.36 sec) Records: 20564 Duplicates: 0 Warnings: 0 Query OK, 20564 rows affected (2.15 sec) Records: 20564 Duplicates: 0 Warnings: 0 Query OK, 20563 rows affected (1.32 sec) Records: 20563 Duplicates: 0 Warnings: 0 Query OK, 20563 rows affected (5.50 sec) Records: 20563 Duplicates: 0 Warnings: 0 Query OK, 4472 rows affected (0.87 sec) Records: 4472 Duplicates: 0 Warnings: 0 Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) Query OK, 0 rows affected (0.00 sec) MariaDB [test]> EXPLAIN SELECT * FROM icp_test WHERE k BETWEEN 4000 AND 5000 AND i < 1000 ORDER BY k ASC LIMIT 10\G *************************** 1. row *************************** id: 1 select_type: SIMPLE table: icp_test type: range possible_keys: k key: k key_len: 8 ref: NULL rows: 223490 Extra: Using index condition 1 row in set (0.11 sec) MariaDB [test]> select @@version; +----------------+ | @@version | +----------------+ | 5.5.27-MariaDB | +----------------+ 1 row in set (0.00 sec)