Originally Posted by Repetitive Monkey

With the suggestions already added in regards to persistent connections and the setting of an index on the "domain" column, I don't have anything to add but a note of the glaring lack of error handling in your script. It shouldn't be a problem for the diligent webmaster, but there is something about the missing safety procedures that irks me any way.

I always use
if(@){
// continue
}else{
// handle as appropriate, whether by continued operation under alternative means or by throwing a custom error
}