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.
Other related distributions: 1  Hyper-exponential distribution â the distribution whose density is a weighted sum of exponential densities. 2  Hypoexponential distribution â the distribution of a general sum of exponential random variables. 3  exGaussian distribution â the sum of an exponential distribution and a normal distribution.