Hashing with Buckets

read

1

6+4 = 10

2

Cluster 1: Adams Coles Flint

Cluster 2: Bates Dean

The problem is that the home address of dean, which is the head of a cluster, is not free

(20)Adams (20)Coles (22)Dean (20)Flint

Two clusters

Overlapped

25

-1

-1

22

23

-1

Solution

3

b >=1, may be more than one slot in

bucket

4

Actual Addresses .See next slide

Applicable to variable

length records

Patterns of records access

Summary : Hashing technique

• Progressive overflow• Other techniques

1. Double hashing2. Chained progressive overflow3. Chaining with a separate overflow area4. Scatter tables

Buckets