----- Original Message ----- > From: "Dave Dyer" <ddyer=my...@real-me.net> > > It depends on if you want the forest or the trees. A frequently > executed query asks for just the robots. An index is an efficient way to > select 6 of 20,000. As for why the rest are null, null is just a a > random everything else value, left over from before the "is_robot" column > was added. > > Is there a better way to mark a small number of "special" records in > a big data set?
No, you're doing it the right way, and the index is used exactly for what it's intended. The NULL is out of place, though - is_robot sounds (and probably is) binary; use it as such and set all the NULLs to 0 instead. NULL means "I really, honestly don't know, there simply is no value for this field". In this case, there is a value: "no, it's not a robot". You may never run into problems with it, or you could slam headfirst into weirdness at some point - NULL has some very peculiar properties that are best avoided if you don't need them. -- 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
