Fifth homework assignment due Tuesday May 20

1. In exercise 13.1, there is a figure 13.20 (page 527) sample history
to be filled in. Omit the step with the checkpoint, as we will cover
checkpoints next week. Fill in the rest of the table. See pages 505 
and page 472 (up to step 21) and 480 (up to step 13) for
answered similar exercises.

2. Here is another exercise like the one above. Fill in the cached
database, the stable database, the log entries in the log buffer and
in the stable log. (remark: if page locking is done, this is not 2PL. This
does not affect the exercise. In most systems, record granularity locking
is used.)

1. begin(t45)
2. write (p1, t45)
3. write (p2, t45)
4. begin (t46)
5. write (p2, t46)
6. write (p3, t45)
7. flush (p2)
8. write (p4, t45)
9. commit(t45)
10. begin (t47)
11. write (p1, t47)
12. write (p3, t47)
13. commit(t46)
14. flush (p3)
15. write (p2, t47)
16. flush (p2)
17. write (p4, t47)
18. commit(t47)