Given the following schema (primary keys are underlined) and SQL query:

Hotel (hotelNo, hotelName, city)
Room (roomNo, hotelNo, type, price)
Booking (hotelNo, guestNo, dateFrom, dateTo, roomNo)
Guest (guestNo, guestName, guestAddress)

SELECT g.guestNo, g.guestName
FROM Room r, Booking b, Hotel h, Guest g
WHERE h.hotelNo = b.hotelNo AND g.guestNo = b.guestNo AND h.hotelNo = r.hotelNo AND
h.hotelName = "Ritz" AND dateFrom >= "Jan 01, 2001" AND dateTo <= "Dec 31, 2001";

a) Draw the initial canonical query tree

b) use heuristic optimization to transform it into the most efficient query tree possible.

Show all intermediate steps and transformations involved. You can make appropriate assumptions for the database statistics to to support your claim.