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.
The relative frequency histogram gives the fraction of times the data occur in the particular group or interval. Relative frequency distribution of a class is the ratio of the frequency of the class to the total number of the items.A uniform distribution often means that the number of classes is too small, each class has about the same number of elements. It may describe a distribution which has several peaks.he relative frequency table is a compact numerical way to present how the data is distributed. If the frequencies are plotted as columns, the resulting plot is called a histogram. A frequency distribution shows the number of items in each of several overlapping classes.