Heap File
=========

Page Header
-----------

 * int freePosition

Item Header
-----------

 * int size

A heap page looks like this:

    |-------------|
    | Page Header |
    |-------------|
    |             |
    | free space  |
    |             |
    |-------------| <-- freePosition
    | Item #2     |
    |   data      |
    |-------------|
    | Item #2     |
    |   header    |
    |-------------|
    | Item #1     |
    |   data      |
    |-------------|
    | Item #1     |
    |   header    |
    |-------------|