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?, rank in asc by the x-axis.
SELECT gender, AVG(age) FROM Person GROUP BY gender ORDER BY gender
SELECT "gender", AVG("age") FROM "Person" GROUP BY "gender" ORDER BY "gender"