Consider the given relational database moviedb which has the following relation schemas:

Movie(title, production year, country, run time, major genre) primary key : {title, production year}

Person(id, first name, last name, year born) primary key : {id}

Director(id, title, production year) primary key : {title, production year} foreign keys : [title, production year] Movie[title, production year] [id] Person[id]

Writer(id, title, production year, credits) primary key : {id, title, production year} foreign keys : [title, production year] Movie[title, production year] [id] Person[id]

Your task is to answer the following questions using SQL queries. For each question, your answer must be a single SQL query that may contain subqueries

2.1 How many writers were born in 1935?

2.2 How many movies were produced in 1993, 1992 and 1991? List the production years and the corresponding numbers of movies.

2.3 How many persons have never directed any movies in this database? List the total number of such persons.

2.4 Who have directed at least two movies that were written by themselves (i.e., a director is one of the writers for the same movie)? Show their ids, first and last names.

2.5 Assume persons who were born in the same year are the same age and there is only one youngest person (with no ties/draws) in this database, who is/are the second youngest person(s) in the database? List the id(s) of the person(s).

2.6 A person has worked on a movie if this person is a director, a writer, or both a director and writer of this movie. Who has/have worked on the largest number of distinct movies in this database? List the id(s) of the person(s).