Histograms
Employee(ssn, name, salary, phone)
•Maintain a histogram on salary:
•T(Employee) = 25000, but now we know the
distribution
500
> 100k
6500
80k..100k
12000
5000
800
200
Tuples
60k..80k
40k..60k
20k..40k
0..20k
Salary: