On 11/8/2010 10:47 PM, wroxdb wrote: > Hello, > > I have a query below: > > mysql> select * from ip_test where 3061579775 between startNum and endNum; > +------------+------------+---------+----------+------+--------+ > | startNum | endNum | country | province | city | isp | > +------------+------------+---------+----------+------+--------+ > | 3061514240 | 3061579775 | 中国 | 河南 | | 联通 | > +------------+------------+---------+----------+------+--------+ > > > the "desc" shows it isn't using the index: > > mysql> desc select * from ip_test where 3061579775 between startNum and > endNum; > +----+-------------+---------+------+-----------------+------+---------+------+--------+-------------+ > | id | select_type | table | type | possible_keys | key | key_len > | ref | rows | Extra | > +----+-------------+---------+------+-----------------+------+---------+------+--------+-------------+ > | 1 | SIMPLE | ip_test | ALL | startNum,endNum | NULL | NULL > | NULL | 396528 | Using where | > +----+-------------+---------+------+-----------------+------+---------+------+--------+-------------+ > 1 row in set (0.01 sec) > > > the table structure is: > > CREATE TABLE `ip_test` ( > `startNum` double(20,0) default NULL, > `endNum` double(20,0) default NULL, > `country` varchar(50) NOT NULL default '', > `province` varchar(50) NOT NULL default '', > `city` varchar(50) NOT NULL default '', > `isp` varchar(100) default NULL, > KEY `startNum` (`startNum`), > KEY `endNum` (`endNum`) > ) ENGINE=MyISAM DEFAULT CHARSET=utf8 > > > > please help, thanks in advance. >
Have you tried a combined index of (startnum,endnum) instead of two single-column indexes? You may still run into problems, though, because ranged searches are usually performed as WHERE column_A BETWEEN X AND Y and not as WHERE X BETWEEN column_A and column_B and the optimizer has been designed to evaluate the first pattern but not the second. -- Shawn Green MySQL Principal Technical Support Engineer Oracle USA, Inc. Office: Blountville, TN -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
