user: Question: How many rankings (timeslot) were there for the episode that aired on May 2, 2010?
Columns: ['#', 'Airdate', 'Episode', 'Rating', 'Share', 'Rating/Share (18–49)', 'Viewers (millions)', 'Rank (Timeslot)', 'Rank (Night)']
Types: ['real', 'text', 'text', 'text', 'real', 'text', 'text', 'real', 'real']
Sample row: [1.0, 'February 14, 2010', '"Nanna Is Kickin\' Your Butt"', '5.1', 8.0, '2.8/7', '9.07', 1.0, 1.0]
SQL:

assistant: SELECT COUNT("Rank (Timeslot)") FROM "Table" WHERE "Airdate" = 'May 2, 2010';