Hi, I have one table : CREATE TABLE `ressources_summary` ( `res_type` tinyint(3) unsigned NOT NULL default '0', `res_id` int(10) unsigned NOT NULL default '0', `comment_count` smallint(5) unsigned NOT NULL default '0', `comment_last_timestamp` timestamp NOT NULL default '0000-00-00 00:00:00', `comment_last_user_id` int(11) NOT NULL default '0', PRIMARY KEY (`res_type`,`res_id`) ) ENGINE=MyISAM
it gather summary on comments for any ressources (poll, articles, forums, admin). A ressource is uniquely identify by (res_type, res_id), the others columns are self-explanatory (I hope). I'm wondering about the efficiency of storing a comment_count of 0 (and user_id=0, timestamp=0). There is comments on 20% of the ressources. What is the cost of looking for a row that does not exists in a table ? Would it be more efficient to only store summary for comment_count greater than 0 and knowing missing rows have a count of zero, or to store everything ? -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
