-1
 CREATE TABLE `words_data` (
  `id` int(11) NOT NULL auto_increment,
  `words` varchar(50) default '',
  `pid` int(8) default '0',
  `baiyephp` int(11) default '0',
  PRIMARY KEY  (`id`),
  KEY `baiyephp` (`baiyephp`),
  KEY `words` (`words`),
  KEY `pid` (`pid`),
  KEY `pid_id` (`id`,`pid`)
 ) ENGINE=MyISAM AUTO_INCREMENT=1961736 DEFAULT CHARSET=utf8

Explain statement: explain select id from words_data where pid=232632; but no possible_keys and no keys listed in the columns.

Himanshu
  • 31,810
  • 31
  • 111
  • 133
yuhai
  • 91
  • 5

1 Answers1

0

Explain yields in my test environment:

Impossible WHERE noticed after reading const tables

Which seems to indicate that there are no data in the table with pid=232632

Alex Monthy
  • 1,827
  • 1
  • 14
  • 24
  • yes,no data in the table with the pid=232632, but there are some rows with the pid = 260009, and also no possible_keys and no keys. – yuhai Sep 05 '12 at 08:32