----- Original Message ----- > From: "Gregory Magarshak" <g...@qbix.com> > I am guessing that the MySQL indexes map indexed fields (fb_uid) to the > primary key (id) so I wouldn't have to touch the disk. Am I right > about that?
Correct for InnoDB, but MyISAM maps every index straight onto records. That's why secondary indices are slightly more performant on MyISAM tables - InnoDB needs to do the extra primary key lookup - which it of course is bloody good at :-) -- Bier met grenadyn Is als mosterd by den wyn Sy die't drinkt, is eene kwezel Hy die't drinkt, is ras een ezel -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/mysql?unsub=arch...@jab.org
