1
Hashing algorithm
2
3
key
45
33
22
11
72
66
70
35
62
68
34
67
Buket size 1
Remainer
11
16
5
11
4
15
2
1
11
0
0
16
divisor = 17
Buket size 2
Remainer
Buket size 3
Remainer
3
5
1
4
2
3
0
0
6
5
6
4
divisor = 7
0 size 1
3 size 2
2 size 3
1
2
1
0
0
2
3
4
2
divisor = 5
Load factor
0.70588235
0.85714286
0.8
The structure of the leaf nodes of a B+-tree of order p
(Figure 14.11b) is as follows:
1.
Each leaf node is of the form
<<K1, Pr1> , <K2, Pr2>, ..., <Kq-1, Prq-1>, Pnext>
2.
3.
4.
5.
Where q 1 p, each Pri is a data pointer, and Pnext points to the next leaf
node of the B+-tree.
Within each leaf node, K1 < K2 < ... < Kq-1, q 1 p.
Each Pri is a data pointer that points to the record whose search field
value is Ki or to a file block containing the record (or to a block of
record pointers that point to records whose search field value is Ki if
the search field is not a key).
Each leaf node has at least (p/2) values.
All leaf nodes are at the same level.
5
6
7
8
B+ Tree
8, 5, 1, 7, 3, 12, 9, 6
(slide 50- book p537)