Among all the tweets with a positive sentiment, what is the percentage of those posted by a male user?
positive sentiment refers to Sentiment > 0; male user refers to Gender = 'Male'; percentage = Divide (Count(TweetID where Gender = 'Male'), Count (TweetID)) * 100
SELECT SUM(CASE WHEN T2.Gender = 'Male' THEN 1.0 ELSE 0 END) / COUNT(T1.TweetID) AS per FROM twitter AS T1 INNER JOIN user AS T2 ON T1.UserID = T2.UserID WHERE T1.Sentiment > 0
database name:db_id social_media
location table location Cols: location id dtype integer, Country dtype text, State dtype text, state code dtype text, City dtype text, 
user table user Cols: user id dtype text, Gender dtype text, 
twitter table twitter Cols: tweet id dtype text, Weekday dtype text, Hour dtype integer, Day dtype integer, language dtype text, is reshare dtype text, Reach dtype integer, retweet count dtype integer, Likes dtype integer, Klout dtype integer, Sentiment dtype real, text dtype text, location id dtype integer, user id dtype text, 
