Query Processing Solution

3a1)          project Book#, Price, Ccity, Order_date
                                |
              select Ccity = "GA", Order_date > 990101, Price > 50
                                | 
               -----------------X------------------  
               |                |                 |
            CUSTOMER          BOOK              ORDER

3a2)                     
                                            |
                                            |
                             --------------join--------------
                             |                              |
               project Book#, Order_idate, Ccity            |
                             |                              |
                 -----------join------------    project Book#, Price 
                 |                         |                |
        project Cid, Ccity                 |           select Price > 50
                 |                         |                |
    select Ccity = "GA"                    |              BOOK
                 |                         |
              CUSTOMER      project Book#, Order_idate, Cid
                                           |
                            select Order_idate > "990101" 
                                           |
                                         ORDER


3b) 1,000,000 / (4.5 million X 1,000,000) = 1 / (4.5 million)
    Note that the answer is not 1 / (1 million) since ORDER join BOOK 
    can't give back more than the number of orders in the DB. 

3c) One topic is 1/1000 of the total database of 4.5 million books, or
    4,500 books. With 100 books to a block, they are stored on 45 blocks.
    Assuming the index is resident in memory, there are then 45 accesses.

    (Using formula S5 in the text, x = 0, because the index is in memory,
    s = 4500, bfr=100, so Cs5 = x + ceil(s/bfr) = 45.)