Why do you think he's having problems with the SQL programming?
Because he hasn't thanked people for help on his twitter feed in reference to SQL database programming.
He also flat-out said : "My database code isn't very efficient. And the more shares I have, the slower it goes.". Having seen the table and the query I'm shocked we even made it to 15 GH. How many 1024 diff shares per second would that be anyway? Not sure how to calculate that.