# 15.00 - Case Study 3 - Teradata Database

prodname
vrm_release
15.00
category
User Guide
featnum
B035-1094-015K

### Case Study 3

The following table indicates the number of distinct occurrences of City column values.

 City Value Frequency of Value Log Frequency of Value New York 4,000 3.602 Los Angeles 4,100 3.613 Chicago 3,800 3.580 Denver 4,200 3.623 Phoenix 3,900 3.591 Atlanta 4,000 3.602 Dallas 3,800 3.580 Boston 4,150 3.618 Paris 30 1.477 London 30 1.477 Tokyo 30 1.477 Rio de Janeiro 30 1.477 Moscow 30 1.477 Mexico City 30 1.477 Kuala Lumpur 30 1.477 Sydney 30 1.477 Brussels 30 1.477

The following histogram graphs the logarithm of the number of rows as a function of row values:

The maximum value for this set is 4,200, but what is the typical value?

It is impossible to determine an accurate “typical” value for the scenario provided by this case history. Like the scenario presented by “Case Study 2” on page 162, the distribution of values has two peaks at widely diverse points in the distribution. Unlike “Case Study 2” the value set clustered around the value 4,000 is not constant.

When you encounter a situation like this, the optimum solution is to use a value around which the largest values cluster as your typical value. In this case, that value is 4,000.

 Maximum Value Typical Value 4,200 4,000