this ppt is about B+ tree Data structure

1. B+ Trees

2. Prepared by
Hamid ali Dana
CS & IT Ajk university Mzd
From Gilgit Baltistan

3. What is b+ tree
A B+ tree is a data structure often used in the
implementation of database indexes. Each
node of the tree contains an ordered list of keys
and pointers to lower level nodes in the tree.
A B+ tree is a balanced tree in which every
path from the root of the tree to a leaf is of the
same length.

4. B+- Tree Characteristics
• Data records are only stored in the leaves.
• Internal nodes store just keys.
• All data is stored at the leaf nodes (leaf pages); all
other nodes (index pages) only store keys.
• All the leaf nodes are interconnected with each other
leaf nodes for faster access.
• Keys are used for directing a search to the proper leaf.
• If a target key is less than a key in an internal node,
then the pointer just to its left is followed.
• If a target key is greater or equal to the key in the
internal node, then the pointer to its right is followed.
• B+ Tree combines features of ISAM (Indexed
Sequential Access Method) and B Trees.

5. B+ TREE
INTERNAL NODE / INDEX nodeS
LEAF NODES / DATA nodeS
The linked list allows rapid traversal.

6. Structure of b+ tree

7. How to create or insert in B+:
==2,4,7,10,17,21,28
if n=4 n is the order
key=n-1=4-1=3
2

8. ==2,4,7,10,17,21,28
2 4

9. ==2,4,7,10,17,21,28
2 4 7

10. ==2,4,7,10,17,21,28
4
2 4 7 10

11. ==2,4,7,10,17,21,28
4 7
2 4 7 10 17

12. ==2,4,7,10,17,21,28
4 7
2 4 7
10
10 17 21

13. ==2,4,7,10,17,21,28
10 17
2 4 7 17 21 28
4
7
10

14. Deletion Process:
Deletion of 28:
10 17
2 4 7 17 21 28
4
7
10

15. Deleted 28:
4 7
2 4 7
10
10 17 21

16. Deletion of 4:
4 7
2 4 7
10
10 17 21

17. Deleted 4:
2 7 10 17
7 10
21

18. Deletion of 7:
2 7 10 17
7 10
21

19. Deleted 7:
2
10
10 17 21

20. Deletion of 2:
2
10
10 17 21

21. Deleted 2:
10 17 21

22. Thank you