This is my present table: CREATE TABLE IF NOT EXISTS `geocode_us` ( `id` int(11) NOT NULL AUTO_INCREMENT, `loc_b` varchar(32) DEFAULT NULL, `loc_a` varchar(32) DEFAULT NULL, `lat` varchar(16) DEFAULT NULL, `lng` varchar(16) DEFAULT NULL, PRIMARY KEY (`id`), UNIQUE KEY `idx_name` (`loc_a`,`loc_b`,`lat`,`lng`), …

DBA told me to do this but did not say why or its advantages? Can someone help Read more »