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

A bar chart about what is average age for different job title?, I want to display by the bars in descending.
SELECT job, AVG(age) FROM Person GROUP BY job ORDER BY job DESC
SELECT "job", AVG("age") FROM "Person" GROUP BY "job" ORDER BY "job" DESC