CS3223 Tutorial 2

1. CS3223 Tutorial 2 Fan Qi fan.qi@nus.edu.sg Database Lab 1, com1 #01-08

2. B+ Tree • Data Entry: • Format 1: actual data record • Format 2: key + RID • Format 3: key, RID-List • Properties & Attributes: • Height Balanced • Every node except root must be half full, [d,2d] • Fanout: # of pointers out of a non-leaf node

3. B+ Tree • Operations: • Search: • Insert: If siblings do not have space, split • Delete: If siblings are just of d, Merge, else borrow one (redistribution) Redistribution in insertion is not frequently used in practice

4. Question 1

5. Question 1 g): Insert 59

6. Question 1 g): Insert 59

7. Question 1 g): Insert 59

8. Question 1 g): Insert 59

9. Question 1 g): Insert 59 Delete 91

10. Question 1 g): Insert 59 Delete 91

11. Question 1 g): Insert 59 Delete 91

12. Question 1 g): Insert 59 Delete 91 Underflow!

13. Question 1 g): Insert 59 Delete 91 Redistribution Failed Merge!

14. Question 1 g): Insert 59 Delete 91 Underflow again!

15. Question 1 g): Insert 59 Delete 91 Redistribution

16. Question 2 • Find level of tree:

17. Question 3 a): Get all records with key C A B

18. Question 3 a): Get all records with key C A B

19. Question 3 a): Get all records with key C A B

20. Question 3 a): Get all records with key C A B

21. Question 3 b): Insert a recode with key 109 C A B Split!!

22. Question 3 b): Insert a recode with key 109 C A B

23. Question 3 d):Which value would result Increasing in tree height? C A B 65-79, assume internal nodes do not re-distribute

24. Question 4 11, 5, 3, 31,19,2,7,17,23,29,4,50,40,44 Top-down

25. Question 4 11, 5, 3, 31,19,2,7,17,23,29,4,50,40,44 Top-down

26. Question 4 11, 5, 3, 31,19,2,7,17,23,29,4,50,40,44 Top-down Split

27. Question 4 11, 5, 3, 31,19,2,7,17,23,29,4,50,40,44 Top-down

28. Question 4 11, 5, 3, 31,19,2,7,17,23,29,4,50,40,44 Top-down Split

29. Question 4 11, 5, 3, 31,19,2,7,17,23,29,4,50,40,44 Top-down

30. Question 4 11, 5, 3, 31,19,2,7,17,23,29,4,50,40,44 Top-down Split

31. Question 4 11, 5, 3, 31,19,2,7,17,23,29,4,50,40,44 Top-down Split

32. Question 4 11, 5, 3, 31,19,2,7,17,23,29,4,50,40,44 Top-down

33. Question 4 11, 5, 3, 31,19,2,7,17,23,29,4,50,40,44 Top-down Split

34. Question 4 11, 5, 3, 31,19,2,7,17,23,29,4,50,40,44 Top-down Further Split

35. Question 4 11, 5, 3, 31,19,2,7,17,23,29,4,50,40,44 Bulk Loading Pros and Cons ?

36. Self Thinking Question • When data has duplication, how to handle it in B+ tree ? • Try to implement a B+ tree by yourself 

37. B+ Tree In Reality

38. Further Doubts? • TA Contact: • Fan Qi • fan.qi@nus.edu.sg • Database Lab 1, com1 #01-08 Happy Chinese New Year !