CREATE TABLE PersonFriend (name VARCHAR2, friend VARCHAR2, year NUMBER)
CREATE TABLE Person (name VARCHAR2, age NUMBER, city CLOB, gender CLOB, job CLOB)

Give me a histogram for how old is each gender, on average?, list in ascending by the mean age.
SELECT gender, AVG(age) FROM Person GROUP BY gender ORDER BY AVG(age)
SELECT "gender", AVG("age") FROM "Person" GROUP BY "gender" ORDER BY AVG("age")