The database commonly uses an index range scan to access selective data. The selectivity is the percentage of rows in the table that the query selects, with 0 meaning no rows and 1 meaning all rows. Selectivity is tied to a query predicate, such as WHERE last_name LIKE 'A%', or a combination of predicates.
Types of Distribution: Intensive, Selective and Exclusive Distribution. Some of the important types of distribution in international market are 1. Intensive 2. Selective and 3. Exclusive distribution.
Galtung introduced a classification system (AJUS) for distributions: 1  A: unimodal distribution â peak in the middle. 2  J: unimodal â peak at either end. 3  U: bimodal â peaks at both ends. 4  S: bimodal or multimodal â multiple peaks.