b

NULL
b


1a20	1e+ 1e+10
1	10000000001
a$1	$b	c$
1	2	3
table	type	possible_keys	key	key_len	ref	rows	Extra
t2	ref	B	B	21	const	1	where used
a	B
3	world
Table	Create Table
t1	CREATE TABLE `t1` (
  `a` int(11) NOT NULL default '0',
  `b` int(11) default NULL,
  PRIMARY KEY  (`a`),
  KEY `b` (`b`),
  KEY `b_2` (`b`),
  KEY `b_3` (`b`),
  KEY `b_4` (`b`),
  KEY `b_5` (`b`),
  KEY `b_6` (`b`),
  KEY `b_7` (`b`),
  KEY `b_8` (`b`),
  KEY `b_9` (`b`),
  KEY `b_10` (`b`),
  KEY `b_11` (`b`),
  KEY `b_12` (`b`),
  KEY `b_13` (`b`),
  KEY `b_14` (`b`),
  KEY `b_15` (`b`),
  KEY `b_16` (`b`),
  KEY `b_17` (`b`),
  KEY `b_18` (`b`),
  KEY `b_19` (`b`),
  KEY `b_20` (`b`),
  KEY `b_21` (`b`),
  KEY `b_22` (`b`),
  KEY `b_23` (`b`),
  KEY `b_24` (`b`),
  KEY `b_25` (`b`),
  KEY `b_26` (`b`),
  KEY `b_27` (`b`),
  KEY `b_28` (`b`),
  KEY `b_29` (`b`),
  KEY `b_30` (`b`),
  KEY `b_31` (`b`)
) TYPE=MyISAM